Preamble Pre.1—Pre.7

 
 
 
 
 
 

I N T E R N A T I O N A L  C O D E  O F  B O T A N I C A L  N O M E N C L A T U R E 
 

                                               P R E A M B L E 
 

1.  Botany requires a precise and simple system of nomenclature used by bota-
nists in all countries, dealing on the one hand with the terms which denote the
ranks of taxonomic groups or units, and on the other hand with the scientific
names which are applied to the individual taxonomic groups of plants. The
purpose of giving a name to a taxonomic group is not to indicate its characters or
history, but to supply a means of referring to it and to indicate its taxonomic
rank. This Code aims at the provision of a stable method of naming taxonomic
groups, avoiding and rejecting the use of names which may cause error or
ambiguity or throw science into confusion. Next in importance is the avoidance
of the useless creation of names. Other considerations, such as absolute gram-
matical correctness, regularity or euphony of names, more or less prevailing
custom, regard for persons, etc., notwithstanding their undeniable importance,
are relatively accessory.

2.  The Principles form the basis of the system of botanical nomenclature.

3.  The detailed Provisions are divided into Rules, set out in the Articles, and
Recommendations. Examples (Ex.) are added to the rules and recommendations
to illustrate them.

4.  The object of the Rules is to put the nomenclature of the past into order and to
provide for that of the future; names contrary to a rule cannot be maintained.

5.  The Recommendations deal with subsidiary points, their object being to
bring about greater uniformity and clearness, especially in future nomenclature;
names contrary to a recommendation cannot, on that account, be rejected, but
they are not examples to be followed.

6.  The provisions regulating the modification of this Code form its last division.

7.  The rules and recommendations apply to all organisms treated as plants
(including fungi but excluding bacteria), whether fossil or non-fossil*. Nomen-

*  In this Code, the term fossil is applied to a taxon when its name is based on a fossil type and the
term ‘non-fossil’ is applied to a taxon when its name is based on a non-fossil type
(see Art. 13.3).

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Pre.8–Pre.l0 Preamble

clature of bacteria is governed by the International Code of Nomenclature of
Bacteria. Special provisions are needed for certain groups of plants: The Inter-
national Code of Nomenclature for Cultivated Plants-1980 was adopted by the
International Commission for the Nomenclature of Cultivated Plants; provi-
sions for the names of hybrids appear in Appendix I.

8.  The only proper reasons for changing a name are either a more profound
knowledge of the facts resulting from adequate taxonomic study or the necessity
of giving up a nomenclature that is contrary to the rules.

9.  In the absence of a relevant rule or where the consequences of rules are
doubtful, established custom is followed.

10.  This edition of the Code supersedes all previous editions.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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Principles I–VI

 
 
 
 
 
 

D I V I S I O N  I.  P R I N C I P L E S
 

Principle I

Botanical nomenclature is independent of zoological nomenclature.

The Code applies equally to names of taxonomic groups treated as plants
whether or not these groups were originally so treated*.

Principle II

The application of names of taxonomic groups is determined by means of
nomenclatural types.

Principle III

The nomenclature of a taxonomic group is based upon priority of publication.

Principle IV

Each taxonomic group with a particular circumscription, position, and rank can
bear only one correct name, the earliest that is in accordance with the Rules,
except in specified cases.

Principle V

Scientific names of taxonomic groups are treated as Latin regardless of their
derivation.

Principle VI

The Rules of nomenclature are retroactive unless expressly limited.

 
 
 
 

*  For the purposes of this Code, ‘plants’ do not include bacteria.

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1–3 Ranks

 
 
 

D I V  I S I O N  I I .   R U L E S  A N D  R E C O M M E N D A T I O N S
 

C H A P T E R  I .  R A N K S  O F  T A X A ,

A N D  T H E  T E R M S  D E N O T I N G  T H E M 
 

Article 1

1.1.  Taxonomic groups of any rank will, in this Code, be referred to as taxa
(singular: taxon).

Article 2

2.1.  Every individual plant is treated as belonging to a number of taxa of
consecutively subordinate ranks, among which the rank of species (species) is
basal.

Article 3

3.1.  The principal ranks of taxa in ascending sequence are: species (species),
genus (genus), family (familia), order (ordo), class (classis), division (divisio), and
kingdom (regnum). Thus, except for some fossil plants (see 3.2), each species is
assignable to a genus, each genus to a family, etc.

3.2.  Because of the fragmentary nature of the specimens on which the species
of some fossil plants are based, the genera to which they are assigned are not
assignable to a family, although they may be referable to a taxon of higher rank.
Such genera are known as form-genera (forma-genera).

Ex. 1.  Not form-genera: Lepidocarpon D. Scott (Lepidocarpaceae), Mazocarpon M. Benson (Sigilla-
riaceae
), Siltaria Traverse (Fagaceae).

Ex. 2.  Form-genera: Dadoxylon Endl. (Coniferopsida), Pecopteris (Brongn.) Sternb. (Pteropsida),
Stigmaria Brongn. (Lepidodendrales), Spermatites Miner (seed-bearing plants).

Note 1.  For the ranks of hybrid taxa, see Art. H.3.1.

Note 2.  Art. 59 provides for form-taxa for asexual forms (anamorphs) of certain pleomorphic fungi,
of any rank.

3.3.  As in the case of certain pleomorphic fungi, the provisions of this Code do
not prevent the publication and use of names of form-genera of fossils.

 
 

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Ranks 4–5

Article 4

4.1.  If a greater number of ranks of taxa is required, the terms for these are made
either by adding the prefixsub-  to the terms denoting the ranks or by the
introduction of supplementary terms. A plant may be assigned to taxa of the
following subordinate ranks:  regnum, subregnum, divisio, subdivisio, classis,
subclassis, ordo, subordo, familia, subfamilia, tribus, subtribus, genus, subgenus,
sectio, subsectio, series, subseries, species, subspecies, varietas, subvarietas, forma,
subforma.

4.2.  Further supplementary ranks may be intercalated or added, provided that
confusion or error is not thereby introduced.

Note 1.  For hybrids and certain variants of species in cultivation, see Appendix I and Art. 28.

Note 2.  In classifying parasites, especially fungi, authors who do not give specific, subspecific or
varietal value to taxa characterized from a physiological standpoint but scarcely or not at all from a
morphological standpoint may distinguish within the species special forms (formae speciales)
characterized by their adaptation to different hosts, but the nomenclature of special forms shall not
be governed by the provisions of this Code.

Article 5

5.1.  The relative order of the ranks specified in Arts. 3 and 4 must not be altered.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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6 Definitions

 
 
 
 
 
 

C H A P T E R  I I .   R A  N K S  O F  T A X A  ( G E N E R A L  P R O V I S I O N S )

S E C T I O N  1 .  D E F I N I T I O N S

Article 6

6.1.  Effective publication is publication in accordance with Arts. 29-31.

6.2.  Valid publication of names is publication in accordance with Arts. 32-45 or
H.9 (see also Art. 75).

6.3.  A legitimate name is one that is in accordance with the rules.

6.4.  An illegitimate name is one that is designated as such in Arts. 18.3 or 63-67
(see also Art. 21 Note 1 and Art. 24 Note 1). A name which according to this
Code was illegitimate when published cannot become legitimate later unless it is
conserved.

6.5.  The correct name of a taxon with a particular circumscription, position, and
rank is the legitimate name which must be adopted for it under the rules (see Art.
11).

Ex. 1.  The generic name Vexillifera Ducke (1922), based on the single species V. micranthera, is
legitimate because it is in accordance with the rules. The same is true of the generic name Dussia Krug
& Urban ex Taubert (1892), based on the single species D. martinicensis. Both generic names are
correct when the genera are thought to be separate. Harms (Repert. Spec. Nov. Regni Veg. 19: 291.
1924), however, united Vexillifera Ducke and Dussia Krug & Urban ex Taubert in a single genus;
when this treatment is accepted the latter name is the only correct one for the genus with this
particular circumscription. The legitimate name Vexillifera may therefore he correct or incorrect
according to different concepts of the taxa.

6.6.  In this Code, unless otherwise indicated, the word name means a name
that has been validly published, whether it is legitimate or illegitimate (see Art.
12).

6.7.  The name of a taxon below the rank of genus, consisting of the name of a
genus combined with one or two epithets, is termed a combination (see Arts. 21,
23, and 24).

Ex. 2.  Combinations: Gentiana lutea, Gentiana tenella var. occidentalis, Equisetum palustre var.
americanum, Equisetum palustre f. fluitans, Mouriri subg. Pericrene, Arytera sect. Mischarytera.

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Typification 7

6.8.  Autonyms are such names as can be established automatically under Arts.
19.4, 22.2, and 26.2, whether they were formally created or not.

S E C T I O N  2 .  T Y P I F I C A T I O N *

Article 7

7.1.  The application of names of taxa of the rank of family or below is deter-
mined by means of nomenclatural types (types of names of taxa). The application
of names of taxa in the higher ranks is also determined by types when the names
are ultimately based on generic names (see Art. 10.5).

7.2.  A nomenclatural type (typus) is that element to which the name of a taxon is
permanently attached, whether as a correct name or as a synonym. The nomen-
clatural type is not necessarily the most typical or representative element of a
taxon.

7.3.  A holotype is the one specimen or other element used by the author or
designated by him as the nomenclatural type. As long as a holotype is extant, it
automatically fixes the application of the name concerned.

7.4.  If no holotype was indicated by the author who described a taxon, or when
the holotype has been lost or destroyed, a lectotype or a neotype as a substitute
for it may be designated. A lectotype always takes precedence over a neotype. An
isotype, if such exists, must be chosen as the lectotype. If no isotype exists, the
lectotype must be chosen from among the syntypes, if such exist. If neither an
isotype nor a syntype nor any of the original material is extant, a neotype may be
selected.

7.5.  A lectotype is a specimen or other element selected from the original
material to serve as a nomenclatural type when no holotype was indicated at the
time of publication or as long as it is missing. When two or more specimens have
been designated as types by the author of a specific or infraspecific name (e.g.
male and female, flowering and fruiting, etc.), the lectotype must be chosen from
among them.

7.6.  An isotype is any duplicate (part of a single gathering made by a collector at
one time) of the holotype; it is always a specimen.

7.7.  A syntype is any one of two or more specimens cited by the author when no
holotype was designated, or any one of two or more specimens simultaneously
designated as types.

7.8.  A neotype is a specimen or other element selected to serve as nomenclatural
 
 

*  See also Guide for the determination of types (p. 79).

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7 Typification

type as long as all of the material on which the name of the taxon was based is
missing.

7.9.  A new name published as an avowed substitute (nomen novum) for an older
name is typified by the type of the older name (see Art. 33.2; but see Art. 33 Note
1).

Ex. 1.  Myrcia lucida McVaugh (1969) was published as a nomen novum for M. laevis O. Berg (1862),
an illegitimate homonym of M. laevis G. Don (1832). The type of M. lucida is therefore the type of M.
laevis
O. Berg (non G. Don), namely, Spruce 3502.

7.10.  A new name formed from a previously published legitimate name (stat.
nov.
, comb. nov.) is, in all circumstances, typified by the type of the basionym (see
Art. 55.2).

Ex. 2.  Iridaea splendens (Setch. & Gardner) Papenf., I. cordata var. splendens (Setch. & Gardner)
Abbott, and Gigartina cordata var. splendens (Setch. & Gardner) Kim all have the same type as their
basionym, Iridophycus splendens Setch. & Gardner, namely, Gardner 7781 (UC 539565).

7.11.  A name which was nomenclaturally superfluous when published (see Art.
63) is automatically typified by the type of the name which ought to have been
adopted under the rules, unless the author of the superfluous name has definitely
indicated a different type.

7.12.  The type of a name of a taxon assigned to a group with a nomenclatural
starting-point later than 1753 (see Art. 13) is to be determined in accordance with
the indication or description and other matter accompanying its valid publica-
tion (see Arts. 32-45).

7.13.  When valid publication is by reference to a pre-starting-point description,
the latter must be used for purposes of typification as though newly published.

7.14.  A change of the listed type of a conserved generic name (see Art. 14 and
App. III) can be effected only by a procedure similar to that adopted for the
conservation of generic names.

Ex. 3.  Bullock and Killick published in Taxon (6: 239. 1957) a proposal that the type of Plectranthus
L’Hér. be changed from P. punctatus (L.f.) L’Hér. to P. fruticosus L’Hér. This proposal was
approved by the appropriate Committees and by an International Botanical Congress.

7.15.  The type of the name of a taxon of fossil plants of the rank of species or
below is the specimen whose figure accompanies or is cited in the valid publica-
tion of the name (see Art. 38). If figures of more than one specimen were given or
cited when the name was validly published, one of those specimens must be
chosen as type.

7.16.  The typification of names of form-genera of plant fossils (Art. 3.2), of
fungal anamorphs (Art. 59), and of any other analogous genera or lower taxa
does not differ from that indicated above.

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Typification 8–9

Note 1.  See also Art. 59 for details regarding typification of names in certain pleomorphic fungi.

7.17.  Typification of names adopted in one of the works specified in Art. 13.1(d),
and thereby sanctioned, is based on everything associated with the name in that
work.

7.18.  The type of an autonym is the same as that of the name from which it is
derived.

Recommendation 7A

7A.1.  It is strongly recommended that the material on which the name of a taxon is based, especially
the holotype, be deposited in a permanent, responsible institution and that it be scrupulously
conserved.

Article 8

8.1.  The author who first designates a lectotype or a neotype must be followed,
but his choice is superseded if the holotype or, in the case of a neotype, any of the
original material is rediscovered; it may also be superseded if it can be shown that
it is in serious conflict with the protologue* and another element is available
which is not in conflict with the protologue, or that it was based on a largely
mechanical method of selection, or that it is contrary to Art. 9.2.

Ex. 1.  Authors following the American Code of Botanical Nomenclature, Canon 15 (Bull. Torrey
Bot. Club 34: 172. 1907), designated as type ‘the first binomial species in order’ eligible under certain
provisions. This
method of selection is considered to be largely mechanical. Thus the lectotypifica-
tion of
Elymus L. by E. arenarius L. (Nash in Britton & Brown, Ill. Fl. N. U.S. ed. 2, 1: 288.1913), the
first species to be listed by Linnaeus, has been superseded by the choice of E. sibiricus L. by Hitchcock
& Green (Nomencl. Prop. Brit. Botanists 121. 1929).

Article 9

9.1.  The type (holotype, lectotype, or neotype) of a name of a species or
infraspecific taxon is a single specimen or other element except in the following
case: for small herbaceous plants and for most non-vascular plants, the type may
consist of more than one individual, which ought to be conserved permanently
on one herbarium sheet or in one equivalent preparation (e.g., box, packet, jar,
microscope slide).

9.2.  If it is later proved that such a type herbarium sheet or preparation contains
parts belonging to more than one taxon, the name must remain attached to that
part (lectotype) which corresponds most nearly with the original description.

Ex. 1.  The holotype of the name Rheedia kappleri Eyma, which applies to a polygamous species, is a
 

*  Protologue (from πρωθος, first, λογος, discourse): everything associated with a name at its valid
publication, i.e., diagnosis, description, illustrations, references, synonymy, geographical data,
citation of specimens, discussion, and comments.

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10 Typification

male specimen collected by Kappler (593a in U). The author designated a hermaphroditic specimen
collected by the Forestry Service of Surinam as a paratype* (B. W. 1618 in U).

Ex. 2.  The type of the name Tillandsia bryoides Griseb. ex Baker (1878) is Lorentz 128 in BM; this,
however, proved to be a mixture. L. B. Smith (Proc. Amer. Acad. Arts 70: 192. 1935) acted in
accordance with this rule in designating one part of Lorentz’s gathering as the lectotype.

9.3.  If it is impossible to preserve a specimen as the type of a name of a species or
infraspecific taxon of non-fossil plants, or if such a name is without a type
specimen, the type may be a description or figure.

9.4.  One whole specimen used in establishing a taxon of fossil plants is to be
considered the nomenclatural type. If this specimen is cut into pieces (sections of
fossil wood, pieces of coal-ball plants, etc.), all parts originally used in establish-
ing the diagnosis ought to be clearly marked.

9.5.  Type specimens of names of taxa must be preserved permanently and
cannot be living plants or cultures.

Recommendation 9A

9A.1.  Whenever practicable a living culture should be prepared from the holotype material of the
name of a newly described taxon of fungi or algae and deposited in a reputable culture collection.
(Such action does not obviate the requirement for a holotype specimen under Art. 9.5.).

Article 10

10.1.  The type of a name of a genus or of any subdivision of a genus** is the type
of a name of
a species (except as provided by Art. 10.3). For purposes of
designation or citation of a type, the species name alone suffices, i.e., it is
considered as the full equivalent of its type.

10.2.  If in the protologue of the name of a genus or of any subdivision of a genus
reference to one or more species names is definitely included, the type must be
chosen from among the types of these names. If no reference to a species name is
definitely included, a type must be otherwise chosen. Such a typification is to be
superseded if it can be demonstrated that the selected type is not conspecific with
any of the material associated with the protologue.

10.3.  By conservation, the type of the name of a genus can be a specimen used by
the author in the preparation of the protologue, other than the type of a name of
an included species.

10.4.  The type of a name of a family or of any subdivision of a family *** is the
same as that of the generic name on which it is based (see Art. 18.1). For purposes
 

*  See Guide for the determination of types, T.4(c).

**  Here and elsewhere in this Code the phrase ‘subdivision of a genus’ refers only to taxa between
genus and species in rank.

***  Here and elsewhere in this Code the phrase ‘subdivision of a family’ refers only to taxa between
family and genus in rank.

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Priority 10

of designation or citation of a type, the generic name alone suffices. The type of a
name of a family or subfamily not based on a generic name is the same as that of
the corresponding alternative name (Arts. 18.5 and 19.7).

10.5.  The principle of typification does not apply to names of taxa above the
rank of family, except for names that are automatically typified by being based
generic names (see Art. 16). The type of such a name is the same as that of the
generic name on which it is based.

 

Note 1.  For the typification of some names of subdivisions of genera see Art. 22.

Recommendation 10A

10A.1.  If the element selected under Art. 10.3 is the type of a species name, that name may be cited as
the type of the generic name. If the element selected is not the type of a species name the type element
should be cited and, optionally, a parenthetical reference to its correct name may be given.

S E C T I O N  3 .  P R I O R I T Y

Article 11

11.1.  Each family or taxon of lower rank with a particular circumscription,
position, and rank can bear only one correct name, special exceptions being
made for 9 families and 1 subfamily for which alternative names are permitted
(see Arts. 18.5 and 19.7). However, the use of separate names for form-taxa of
fungi and for form-genera of fossil plants is allowed under Arts. 3.3 and 59.5.

11.2.  For any taxon from family to genus inclusive, the correct name is the
earliest legitimate one with the same rank, except in cases of limitation of priority
by conservation (see Art. 14) or where Arts. 13.1(d), 19.3, 58, or 59 apply.

11.3.  For any taxon below the rank of genus, the correct name is the combina-
tion of the final epithet* of the earliest legitimate name of the taxon in the same
rank with the correct name of the genus or species to which it is assigned, except
(a) in cases of limitation of priority under Arts. 13.1(d) and 14, or (b) if the
resulting combination would be invalid under Art.
32.1(b) or illegitimate under
Art.
64, or (c) if Arts. 22.1, 26.1, 58, or 59 rule that a different combination is to
be used
.

11.4.  The principle of priority is not mandatory for names of taxa above the
rank of family (but see Rec. 16B).

 
 
 
 

*  Here and elsewhere in this Code, the phrase ‘final epithet’ refers to the last epithet in sequence in
one particular combination, whether that of a subdivision of a genus or of a species or of an
infraspecific taxon.

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12–13 Starting points

Article 12

12.1.  A name of a taxon has no status under this Code unless it is validly
published (see Arts. 3245).

S E C T I O N  4 .  L I M I T A T I O N  O F  T H E  P R I N C I P L E  O F  P R I O R I T Y

Article 13

13.1.  Valid publication of names for plants of the different groups is treated as
beginning at the following dates (for each group a work is mentioned which is
treated as having been published on the date given for that group):

Non-fossil plants:

(a)  SPERMATOPHYTA and PTERIDOPHYTA, 1 May 1753 (Linnaeus, Species Planta-
      rum ed. 1).

(b)  MUSCI (the Sphagnaceae excepted), 1 Jan. 1801 (Hedwig, Species Musco-
      rum).

(c)  SPHAGNACEAE and HEPATICAE, 1 May 1753 (Linnaeus, Species Plantarum
      ed. 1).

(d)  FUNGI: (including Myxomycetes and lichen-forming fungi), 1 May 1753
      (Linnaeus, Species Plantarum ed. 1). Names in the Uredinales, Ustilaginales,
      and Gasteromycetes adopted by Persoon (Synopsis Methodica Fungorum,
      31 Dec. 1801) and names of Fungi Caeteri (excluding Myxomycetes and
      lichen-forming fungi) adopted by Fries (Systema Mycologicum, vols. 1 (1
      Jan. 1821) to 3, and Elenchus Fungorum, vols. 1–2), are sanctioned, i.e., are
      treated as if conserved against earlier homonyms and competing synonyms.
      For nomenclatural purposes names given to lichens shall be considered as
      applying to their fungal component.

(e)  ALGAE, 1 May 1753 (Linnaeus, Species Plantarum ed. 1). Exceptions:
      NOSTOCACEAE HOMOCYSTEAE, 1 Jan. 1892 (Gomont, Monographie des Oscil-
      lariées, Ann. Sci. Nat. Bot. ser. 7, 15: 263–368; 16: 91–264). The two parts of
      Gomont’s ‘Monographie’, which appeared in 1892 and 1893 respectively,
      are treated as having been published simultaneously on 1 Jan. 1892.
      NOSTOCACEAE HETEROCYSTEAE, 1 Jan. 1886 (Bornet & Flahault, Révision des
      Nostocacées hétérocystées, Ann. Sci. Nat. Bot. ser. 7, 3: 323–381; 4: 343–373;
      5: 51–129; 7: 177–262). The four parts of the ‘Révision’, which appeared in
      1886, 1886, 1887, and 1888 respectively, are treated as having been published
      simultaneously on 1 Jan. 1886.
      DESMIDIACEAE, 1 Jan. 1848 (Ralfs, British Desmidieae).
      OEDOGNIACEAE, 1 Jan. 1900 (Hirn, Monographie und Iconographie der
      Oedogoniaceen, Acta Soc. Sci. Fenn. 27(1)).
 
 

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Conservation 14

Fossil plants:

(f)  ALL GROUPS 31 Dec. 1820 (Sternberg, Flora der Vorwelt, Versuch 1: 1–24. t
      1–13). Schlotheim, Petrefactenkunde, 1820, is regarded as published before
      31 Dec. 1820.
 

13.2.  The group to which a name is assigned for the purposes of this Article is
determined by the accepted taxonomic position of the type of the name.

Ex. 1.  The genus Porella and its single species, P. pinnata, were referred by Linnaeus (1753) to the
Musci; if the type specimen of P. pinnata is accepted as belonging to the Hepaticae, the names were
validly published in 1753.

Ex. 2.  The lectotype of Lycopodium L. (1753) is L. clavatum L. (1753) and the type specimen of this is
currently accepted as a pteridophyte. Accordingly, although the genus is listed by Linnaeus among
the Musci, the generic name and the names of the pteridophyte species included by Linnaeus under it
were validly published in 1753.

13.3.  For nomenclatural purposes, a name is treated as pertaining to a non-fossil
taxon unless its type is fossil in origin. Fossil material is distinguished from non-
fossil
material by stratigraphic relations at the site of original occurrence. In
cases of doubtful stratigraphic relations, provisions for non-fossil taxa apply.

13.4.  Generic names which first appear in Linnaeus’ Species Plantarum ed. 1
(1753) and ed. 2 (1762–63) are associated with the first subsequent description
given under those names in Linnaeus’ Genera Plantarum ed. 5 (1754) and ed. 6
(1764) (see Art. 41). The spelling of the generic names included in the Species
Plantarum ed. 1 is not to be altered because a different spelling has been used in
the Genera Plantarum ed. 5.

13.5.  The two volumes of Linnaeus’ Species Plantarum ed. 1 (1753), which
appeared in May and August, 1753, respectively, are treated as having been
published simultaneously on the former date (1 May 1753).

Ex. 3.  The generic names Thea L. Sp. Pl. 515 (May 1753) and Camellia L. Sp. Pl. 698 (Aug. 1753),
Gen. Pl. ed. 5. 311 (1754) are treated as having been published simultaneously in May 1753. Under
Art. 57 the combined genus bears the name Camellia, since Sweet (Hort. Suburb. Lond. 157. 1818),
who was the first to unite the two genera, chose that name, citing Thea as a synonym.

13.6.  Names of anamorphs of fungi with a pleomorphic life cycle do not,
irrespective of priority, affect the nomenclatural status of the names of the
correlated holomorphs (see Art. 59.4).

Article 14

14.1.  In order to avoid disadvantageous changes in the nomenclature of fami-
lies, genera, and species entailed by the strict application of the rules, and
especially of the principle of priority in starting from the dates given in Art. 13,
this Code provides, in Appendices II and III, lists of names that are conserved
(nomina conservanda) and must be retained as useful exceptions.

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14 Conservation

14.2.  Conservation aims at retention of those names which best serve stability of
nomenclature (see Rec. 50E). Conservation of specific names is restricted to
species of major economic importance.

14.3.  The application of both conserved and rejected names is determined by
nomenclatural types.

14.4.  A conserved name of a family or genus is conserved against all other names
in the same rank based on the same type (nomenclatural synonyms, which are to
be rejected) whether these are cited in the corresponding list of rejected names or
not, and against those names based on different types (taxonomic synonyms)
that are cited in that list*. A conserved name of a species is conserved against all
names listed as rejected, and against all combinations based on the rejected
names.

14.5.  When a conserved name competes with one or more other names based on
different types and against which it is not explicitly conserved, the earliest of the
competing names is adopted in accordance with Art. 57.1, except for conserved
family names (
Appendix II), which are conserved against unlisted names.

Ex. 1.  If the genus Weihea Sprengel (1825) is united with Cassipourea Aublet (1775), the combined
genus will bear the prior name Cassipourea, although Weihea is conserved and Cassipourea is not.

Ex. 2.  If Mahonia Nutt. (1818) is united with Berberis L. (1753), the combined genus will bear the
prior name Berberis, although Mahonia is conserved.

Ex. 3.  Nasturtium R. Br. (1812) was conserved only against the homonym Nasturtium Miller (1754)
and the nomenclatural synonym Cardaminum Moench (1794); consequently if reunited with Rorippa
Scop. (1760) it must bear the name Rorippa.

14.6.  When a name of a taxon has been conserved against an earlier name based
on a different type, the latter is to be restored, subject to Art. 11, if it is considered
the name of a taxon at the same rank distinct from that of the nomen conservan-
dum
except when the earlier rejected name is a homonym of the conserved name.

Ex. 4.  The generic name Luzuriaga Ruiz & Pavón (1802) is conserved against the earlier names
Enargea Banks & Sol. ex Gaertner (1788) and Callixene Comm. ex A. L. Juss. (1789). If, however,
Enargea Banks & Sol. ex Gaertner is considered to be a separate genus, the name Enargea is retained
for it.

14.7.  A rejected name, or a combination based on a rejected name, may not be
restored for a taxon which includes the type of the corresponding conserved
name.

Ex. 5.  Enallagma Baillon (1888) is conserved against Dendrosicus Raf. (1838), but not against
Amphitecna Miers (1868); if Enallagma and Amphitecna are united, the combined genus must bear
the name Amphitecna, although the latter is not explicitly conserved against Dendrosicus.

*  The International Code of Zoological Nomenclature and the International Code of Nomenclature
of Bacteria use the terms ‘objective synonym’ and ‘subjective synonym’ for nomenclatural and
taxonomic synonym, respectively.

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Conservation 15

14.8.  A name may be conserved with a different type from that designated by the
author or determined by application of the Code (see Art. 10.3). A name with a
type so conserved (typ. cons.) is legitimate even if it would otherwise be illegiti-
mate under Art. 63. When a name is conserved with a type different from that of
the original author, the author of the name as conserved, with the new type, must
be cited.

Ex. 6.  Bulbostylis Kunth (1837), nom. cons. (non Bulbostylis Steven 1817). This is not to be cited as
Bulbostylis Steven emend. Kunth, since the type listed was not included in Bulbostylis by Steven in
1817.

14.9.  A conserved name, and the corresponding autonyms, are conserved against
all earlier homonyms.

Ex. 7.  The generic name Smithia Aiton (1789), conserved against Damapana Adanson (1763), is
thereby conserved automatically against the earlier homonym Smithia Scop. (1777).

14.10.  A name can be conserved in order to preserve a particular orthography. A
name so conserved
is to be attributed without change of priority to the author
who validly published it, not to the author whose spelling is conserved.

Ex. 8.  The spelling Rhodymenia, used by Montagne (1839), has been conserved against the original
spelling Rhodomenia, used by Greville (1830). The name is to be cited as Rhodymenia Grev. (1830).

14.11.  The lists of conserved names will remain permanently open for additions
and changes. Entries of conserved names cannot be deleted. Any proposal of an
additional name must be accompanied by a detailed statement of the cases both
for and against its conservation. Such proposals must be submitted to the
General Committee (see Division III), which will refer them for examination to
the committees for the various taxonomic groups.

Article 15

15.1.  When a proposal for the conservation (or rejection under Art. 69) of
a name has been approved by the General Committee after study by the Commit-
tee for the taxonomic group concerned, retention (or rejection) of that name is
authorized subject to the decision of a later International Botanical Congress.

Recommendation 15A

15A.1.  When a proposal for the conservation or rejection of a name has been referred to the
appropriate Committee for study, authors should follow existing usage as far as possible pending the
General Committee’s recommendation on the proposal.

 
 
 
 
 

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16 Higher taxa

 
 
 
 
 
 

C H A P T E R  I I I .   N O M E N C L A T U R E  O F  T A X A  A C C O R D I N G  T O

T H E I R  R A N K 
 
 

S E C T I O N 1 . N A M E S  O F  T A X A  A B O V E  T H E  R A N K  O F  F A M I L Y

Article 16

16.1.  Names of taxa above the rank of family are automatically typified if they
are based on generic names (see Art. 10.5); for such automatically typified
names, the name of a subdivision which includes the type of the adopted name
of a division, the name of a subclass which includes the type of the adopted name
of a class, and the name of a suborder which includes the type of the adopted name
of an order, are to be based on the generic name equivalent to that type, but
without the citation of an author’s name
.

16.2.  Where one of the stems -monado-, -cocco-, -nemato-, or -clado- as the
second part of a generic name has been omitted before the termination -phyceae
or -phyta, the shortened class or division name is regarded as based on the generic
name in question if such derivation is obvious or is indicated at establishment of
the group name.

Ex. 1.  Raphidophyceae Chadefaud ex P. C. Silva (1980) was indicated by its author to be based on
Raphidomonas F. Stein (1878).

Note 1.  The principle of priority is not mandatory for names of taxa above the rank of family (Art.
11.4).

Recommendation 16A

16A.1.  The name of a division is taken either from distinctive characters of the division (descriptive
names) or from a name of an included genus; it should end in -phyta, except when it is a division of
fungi, in which case it should end in -mycota.

16A.2.  The name of a subdivision is formed in a similar manner; it is distinguished from a divisional
name by an appropriate prefix or suffix or by the termination -phytina, except when it is a subdivision
of fungi, in which case it should end in -mycotina.

16A.3.  The name of a class or of a subclass is formed in a similar manner and should end as follows:

(a)  In the Algae: -phyceae (class) and -phycidae (subclass);

(b)  In the Fungi: -mycetes (class) and -mycetidae (subclass);

(c)  In the Cormophyta: -opsida (class) and -idae (subclass).

16A.4.  When a name has been published with a termination not agreeing with this recommendation,
the termination may be changed to accord with it, without change of author’s name or date of
publication.

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Families 17–18

Recommendation 16B

16B.1.  In choosing among typified names for a taxon above the rank of family, authors should
generally follow the principle of priority.

Article 17

17.1.  The name of an order or suborder is taken either from distinctive charac-
ters of the taxon (descriptive name) or from a legitimate name of an included
family based on a generic name (automatically typified name). An ordinal name
of the second category is formed by adding the termination -ales to the stem of
the name of the genus. A subordinal name of the second category is similarly
formed, with the termination -ineae.

Ex. 1.  Descriptive names of orders:  Centrospermae, Parietales, Farinosae; of a suborder:  Enantio-
blastae
.

Ex. 2.  Automatically typified names:  Fucales, Polygonales, Ustilaginales; Bromeliineae, Malvineae.

17.2.  Names intended as names of orders, but published with their rank denoted
by a term such as ‘cohors’, ‘nixus’, ‘alliance’, or ‘Reihe’ instead of order’, are
treated as having been published as names of orders.

17.3.  When the name of an order or suborder based on a name of a genus has
been published with an improper termination, this termination must be changed
to accord with the rule, without change of the author’s name or date of publica-
tion.

Recommendation 17A

17A.1.  Authors should not publish new names of orders for taxa of that rank which include a family
from whose name an existing ordinal name is derived.

S E C T I O N  2 .  N A M E S  O F  F A M I L I E S  A N D  S U B F A M I L I E S ,

T R I B E S  A N D  S U B T R I B E S

Article 18

18.1.  The name of a family is a plural adjective used as a substantive; it is formed
by adding the termination -aceae to the stem of a legitimate name of an included
genus (see also Art. 10). (For the treatment of final vowels of stems in composi-
tion, see Rec. 73G).

Ex. 1.  Rosaceae (from Rosa), Salicaceae (from Salix), Plumbaginaceae (from Plumbago).

18.2.  Names intended as names of families, but published with their rank
denoted by one of the terms ‘order’ (ordo) or ‘natural order’ (ordo naturalis)
instead of ‘family’, are treated as having been published as names of families.

18.3.  A name of a family based on the stem of an illegitimate generic name is

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19 Subdivisions of families

illegitimate unless conserved. Contrary to Art. 32.1(b) such a name is validly
published if it complies with the other requirements for valid publication.

Ex. 2.  Caryophyllaceae, nom. cons. (from Caryophyllus Miller non L.); Winteraceae, nom. cons.
(from Wintera Murray, an illegitimate synonym of Drimys Forster & Forster f.).

18.4.  When a name of a family has been published with an improper Latin
termination, the termination must be changed to conform with the rule, without
change of the author’s name or date of publication (see Art. 32.5).

Ex. 3.  Coscinodisceae Kütz. is to be accepted as Coscinodiscaceae Kütz. and not attributed to De
Toni, who first used the correct spelling (Notarisia 5: 915. 1890).

Ex. 4.  Atherospermeae R. Br. is to be accepted as Atherospermataceae R. Br. and not attributed to
Airy Shaw (in Willis, Dict. Fl. Pl. ed. 7. 104. 1966), who first used the correct spelling, or to Lindley,
who used the spelling Atherospermaceae (Veg. Kingd. 300. 1846).

Ex. 5.  However, Tricholomées Roze (Bull. Soc. Bot. France 23: 49. 1876) is not to be accepted as
Trichotomataceae Roze, because it has a French rather than a Latin termination.

18.5.  The following names, sanctioned by long usage, are treated as validly
published: Palmae (Arecaceae; type, Areca L.); Gramineae (Poaceae; type, Poa
L.); Cruciferae (Brassicaceae; type, Brassica L.); Leguminosae (Fabaceae; type,
Faba Miller (= Vicia L. p.p.)); Guttiferae (Clusiaceae; type, Clusia L.); Umbelli-
ferae
(Apiaceae; type, Apium L.); Labiatae (Lamiaceae; type, Lamium L.); Com-
positae
(Asteraceae; type, Aster L.). When the Papilionaceae (Fabaceae; type,
Faba Miller) are regarded as a family distinct from the remainder of the Legumi-
nosae,
the name Papilionaceae is conserved against Leguminosae (see Art. 51.2).

18.6.  The use, as alternatives, of the names indicated in parentheses in Art. 18.5
is authorized.

Article 19

19.1.  The name of a subfamily is a plural adjective used as a substantive; it is
formed by adding the termination -oideae to the stem of a legitimate name of an
included genus.

19.2.  A tribe is designated in a similar manner, with the termination -eae, and a
subtribe similarly with the termination -inae.

19.3.  The name of any subdivision of a family that includes the type of the
adopted, legitimate name of the family to which it is assigned is to be based on the
generic name equivalent to that type, but not followed by an author’s name (see
Art. 46). Such names are termed autonyms (Art. 6.8; see also Art. 7.18).

Ex. 1.  The type of the family name Rosaceae A. L. Juss. is Rosa L. and hence the subfamily and tribe
which include Rosa are to be called Rosoideae and Roseae.

Ex. 2.  The type of the family name Poaceae Barnhart (nom. alt., Gramineae A. L. Juss. — see Art.

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Subdivisions of families 19

18.5) is Poa L. and hence the subfamily and tribe which include Poa are to be called Pooideae and
Poëae.

Note 1.  This provision applies only to the names of those subordinate taxa that include the type of
the adopted name of the family (but see Rec. 19A).

Ex. 3.  The subfamily including the type of the family name Ericaceae A. L. Juss. (Erica L.) is called
Ericoideae, and the tribe including this type is called Ericeae. However, the correct name of the tribe
including both Rhododendron L., the type of the subfamily name Rhododendroideae Endl., and
Rhodora L. is Rhodoreae G. Don (the oldest legitimate name), and not Rhododendreae.

Ex. 4.  The subfamily of the family Asteraceae Dumort. (nom. alt., Compositae Giseke) including
Aster L., the type of the family name, is called Asteroideae, and the tribe and subtribe including Aster
are called Astereae and Asterinae, respectively. However, the correct name of the tribe including both
Cichorium L., the type of the subfamily name Cichorioideae Kitamura, and Lactuca L. is Lactuceae
Cass., not Cichorieae, while that of the subtribe including both Cichorium and Hyoseris L. is
Hyoseridinae Less., not Cichoriinae (unless the Cichoriaceae A. L. Juss. are accepted as a family
distinct from Compositae).

19.4.  The first valid publication of a name of a subdivision of a family that does
not include the type of the adopted, legitimate name of the family automatically
establishes the corresponding autonym (see also Arts. 32.6 and 57.3).

19.5.  The name of a subdivision of a family may not be based on the same stem
of a generic name as is the name of the family or of any subdivision of the same
family unless it has the same type as that name.

19.6.  When a name of a taxon assigned to one of the above categories has been
published with an improper Latin termination, such as -eae for a subfamily or
-oideae for a tribe, the termination must be changed to accord with the rule,
without change of the author’s name or date of publication (see Art. 32.5).

Ex. 5.  The subfamily name Climacieae Grout (Moss Fl. N. Amer. 3: 4. 1928) is to be changed to
Climacioideae with rank and author’s name unchanged.

19.7.  When the Papilionaceae are included in the family Leguminosae (nom.alt.,
Fabaceae; see Art. 18.5) as a subfamily, the name Papilionoideae may be used as
an alternative to Faboideae.

Recommendation 19A

19A.1.  If a legitimate name is not available for a subdivision of a family which includes the type of the
correct name of another taxon of higher or lower rank (e.g., subfamily, tribe, or subtribe), but not of
the family to which it is assigned, the new name of that taxon should be based on the same generic
name as the name of the higher or lower taxon.

Ex. 1.  Three tribes of the family Ericaceae, none of which includes the type of that family name
(Erica L.), are Pyroleae D. Don, Monotropeae D. Don, and Vaccinieae D. Don. The names of the
later-described subfamilies Pyroloideae (D. Don) A. Gray, Monotropoideae (D. Don) A. Gray, and
Vaccinioideae (D. Don) Endl. are based on the same generic names.

 
 
 

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20 Genera

S E C T I O N  3  .   N A M E S  O F  G E N E R A  A N D  S U B D I V I S I O N S  O F  G E N E R A

Article 20

20.1.  The name of a genus is a substantive in the singular number, or a word
treated as such. It may be taken from any source whatever, and may even be
composed in an absolutely arbitrary manner.

Ex. 1.  Rosa, Convolvulus, Hedysarum, Bartramia, Liquidambar, Gloriosa, Impatiens, Rhododendron,
Manihot, Ifloga
(an anagram of Filago).

20.2.  The name of a genus may not coincide with a technical term currently used
in morphology unless it was published before 1 Jan. 1912 and accompanied by a
specific name published in accordance with the binary system of Linnaeus.

Ex. 2.  The generic name Radicula Hill (1756) coincides with the technical term radicula (radicle)
and was not accompanied by a specific name in accordance with the binary system of Linnaeus. The
name is correctly attributed to Moench (1794), who first combined it with specific epithets, but at that
time he included in the genus the type of the generic name Rorippa Scop. (1760). Radicula Moench is
therefore rejected in favour of Rorippa.

Ex. 3.  Tuber Wigg. : Fr., when published in 1780, was accompanied by a binary specific name (Tuber
gulosorum
Wigg.) and is therefore validly published.

Ex. 4.  The generic names Lanceolatus Plumstead (1952) and Lobata V. J. Chapman (1952) coincide
with technical terms and are therefore not validly published.

Ex. 5.  Names such as Radix, Caulis, Folium, Spina, etc., cannot now be validly published as generic
names.

20.3.  The name of a genus may not consist of two words, unless these words are
joined by a hyphen.

Ex. 6.  The generic name Uva ursi Miller (1754) as originally published consisted of two separate
words unconnected by a hyphen, and is therefore rejected; the name is correctly attributed to
Duhamel (1755) as Uva-ursi (hyphened when published).

Ex. 7.  However, names such as Quisqualis (formed by combining two words into one when original-
ly published), Sebastiano-schaueria, and Neves-armondia (both hyphened when originally published)
are validly published.

Note 1. The names of intergeneric hybrids are formed according to the provisions of Appendix I,
Art. H.6.

20.4.  The following are not to be regarded as generic names:

(a)  Words not intended as names.

Ex. 8.  Anonymos Walter (Fl. Carol. 2, 4, 9, etc. 1788) is rejected as being a word applied to 28
different genera by Walter to indicate that they were without names.

Ex. 9.  Schaenoides and Scirpoides, as used by Rottbøll (Descr. Pl. Rar. Progr. 14, 27. 1772) to
indicate unnamed genera resembling Schoenus and Scirpus which he stated (on page 7) he intended to
name later, are token words and not generic names. Kyllinga Rottb. and Fuirena Rottb. (1773) are the
first legitimate names of these genera.

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Subdivisions of genera 21

(b)  Unitary designations of species.

Ex. 10.  Ehrhart (Phytophylacium 1780, and Beitr. 4: 145-150. 1789) proposed unitary names for
various species known at that time under binary names, e.g. Phaeocephalum for Schoenus fuscus, and
Leptostachys for Carex leptostachys. These names, which resemble generic names, should not be
confused with them and are to be rejected, unless they have been published as generic names by a
subsequent author; for example, the name Baeothryon, employed as a unitary name of a species by
Ehrhart, was subsequently published as a generic name by A. Dietrich.

Ex. 11.  Necker in his Elementa Botanica, 1790, proposed unitary designations for his ‘species
naturales’. These names, which resemble generic names, are not to be treated as such, unless they
have been published as generic names by a subsequent author; for example Anthopogon, employed by
Necker for one of his ‘species naturales’, was published as a generic name by Rafinesque: Anthopogon
Raf. non Nutt.

Recommendation 20A

20A.1.  Authors forming generic names should comply with the following suggestions:

(a)  To use Latin terminations insofar as possible.

(b)  To avoid names not readily adaptable to the Latin language.

(c)  Not to make names which are very long or difficult to pronounce in Latin.

(d)  Not to make names by combining words from different languages.

(e)  To indicate, if possible, by the formation or ending of the name the affinities or analogies of the
       genus.

(f)  To avoid adjectives used as nouns.

(g)  Not to use a name similar to or derived from the epithet of one of the species of the genus.

(h)  Not to dedicate genera to persons quite unconnected with botany or at least with natural science.

(i)   To give a feminine form to all personal generic names, whether they commemorate a man or a
       woman (see Rec. 73B).

(j)   Not to form generic names by combining parts of two existing generic names, e.g. Hordelymus
       from Hordeum and Elymus, because such names are likely to be confused with nothogeneric
       names (see Art. H.6).

Article 21

21.1.  The name of a subdivision of a genus is a combination of a generic name
and a subdivisional epithet connected by a term (subgenus, sectio, series, etc.)
denoting its rank.

21.2.  The epithet is either of the same form as a generic name, or a plural
adjective agreeing in gender with the generic name and written with a capital
initial letter (see Art. 32.5).

21.3.  The epithet of a subgenus or section is not to be formed from the name of
the genus to which it belongs by adding the prefix Eu-.

Ex. 1.  Costus subg. Metacostus; Ricinocarpos sect. Anomodiscus; Sapium subsect. Patentinervia;
Valeriana sect. Valerianopsis; Euphorbia sect. Tithymalus; Euphorhia subsect. Tenellae; Arenaria ser.
Anomalae;
but not Carex sect. Eucarex.

Note 1. The use within the same genus of the same epithet in names of subdivisions of the genus, even
in different ranks, based on different types is illegitimate under Art. 64.

Note 2. The names of hybrids with the rank of a subdivision of a genus are formed according to the
provisions of Appendix I, Art. H.7

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22 Subdivisions of genera

Recommendation 21A

21A.1.  When it is desired to indicate the name of a subdivision of the genus to which a particular
species belongs in connection with the generic name and specific epithet, its epithet should be placed
in parentheses between the two; when desirable, its rank may also be indicated.

Ex. 1.  Astragalus (Cycloglottis) contortuplicatus; Astragalus (Phaca) umbellatus; Loranthus (sect.
Ischnanthus) gabonensis.

Recommendation 21B

21B.1.  The epithet of a subgenus or section is preferably a substantive, that of a subsection or lower
subdivision of a genus preferably a plural adjective.

21B.2.  Authors, when proposing new epithets for subdivisions of genera, should avoid those in the
form of a substantive when other co-ordinate subdivisions of the same genus have them in the form of
a plural adjective, and vice-versa. They should also avoid, when proposing an epithet for a
subdivision of a genus, one already used for a subdivision of a closely related genus, or one which is
identical with the name of such a genus.

Article 22

22.1.  The name of any subdivision of a genus that includes the type of the
adopted, legitimate name of the genus to which it is assigned is to repeat that
generic name unaltered as its epithet, but not followed by an author’s name (see
Art. 46). Such names are termed autonyms (Art. 6.8; see also Art. 7.18).

Note 1. This provision applies only to the names of those subordinate taxa that include the type of
the adopted name of the genus (but see Rec. 22A).

22.2.  The first valid publication of a name of a subdivision of a genus that does
not include the type of the adopted, legitimate name of the genus automatically
establishes the corresponding autonym (see also Arts. 32.6 and 57.3).

Ex. 1.  The subgenus of Malpighia L. which includes the lectotype of the generic name (M. glabra L.)
is called Malpighia subg. Malpighia, and not Malpighia subg. Homoiostylis Niedenzu.

Ex. 2.  The section of Malpighia L. including the lectotype of the generic name is called Malpighia
sect. Malpighia, and not Malpighia sect. Apyrae DC.

Ex. 3.  However, the correct name of the section of the genus Rhododendron L. which includes
Rhododendron luteum Sweet, the type of Rhododendron subg. Anthodendron (Reichenb.) Rehder, is
Rhododendron sect. Pentanthera G. Don, the oldest legitimate name for that section, and not
Rhododendron sect. Anthodendron.

22.3.  The epithet in the name of a subdivision of a genus may not repeat
unchanged the correct name of the genus, except when the two names have the
same type.

22.4.  When the epithet of a subdivision of a genus is identical with or derived
from the epithet of one of its constituent species, the type of the name of the
subdivision of the genus is the same as that of the species name, unless the
original author of the subdivisional name designated another type.

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Species 23

Ex. 4.  The type of Euphorbia subg. Esula Pers. is E. esula L.; the designation of E. peplus L. as
lectotype by Croizat (Revista Sudamer. Bot. 6: 13. 1939) is rejected.

Ex. 5.  The type of Lobelia sect. Eutupa Wimmer is L. tupa L.

22.5.  When the epithet of a subdivision of a genus is identical with or derived
from the epithet of a specific name that is a later homonym, it is the type of that
later homonym, whose correct name necessarily has a different epithet, that is the
nomenclatural type.

Recommendation 22A

22A.1.  A section including the type of the correct name of a subgenus, but not including the type of
the correct name of the genus, should, where there is no obstacle under the rules, be given a name with
the same epithet and type as the subgeneric name.

22A.2.  A subgenus not including the type of the correct name of the genus should, where there is no
obstacle under the rules, be given a name with the same epithet and type as a name of one of its
subordinate sections.

Ex. 1.  Instead of using a new name at the subgeneric level, Brizicky raised Rhamnus sect. Pseudofran-
gula
Grubov to the rank of subgenus as Rhamnus subg. Pseudofrangula (Grubov) Briz. The type of
both names is the same, R. alnifolia L’Hér.

S E C T I O N  4  .  N A M E S  O F  S P E C I E S

Article 23

23.1.  The name of a species is a binary combination consisting of the name of the
genus followed by a single specific epithet. If an epithet consists of two or more
words, these are to be united or hyphened. An epithet not so joined when
originally published is not to be rejected but, when used, is to be united or
hyphened (see Art. 73.9).

23.2.  The epithet in the name of a species may be taken from any source
whatever, and may even be composed arbitrarily.

Ex. 1.  Cornus sanguinea, Dianthus monspessulanus, Papaver rhoeas, Uromyces fabae, Fumaria gusso-
nei, Geranium robertianum, Embelia sarasiniorum, Atropa bella-donna, Impatiens noli-tangere, Adian-
tum capillus-veneris, Spondias mombin
(an indeclinable epithet).

23.3.  Symbols forming part of specific epithets proposed by Linnaeus must be
transcribed.

Ex. 2.  Scandix pecten ♀ L. is to be transcribed as Scandix pecten-veneris; Veronica anagallis ∇ L. is to
be transcribed as Veronica anagallis-aquatica.

23.4.  The specific epithet may not exactly repeat the generic name with or
without the addition of a transcribed symbol (tautonym).

Ex. 3.  Linaria linaria, Nasturtium nasturtium-aquaticum.

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22 Subdivisions of genera

23.5.  The specific epithet, when adjectival in form and not used as a substantive,
agrees grammatically with the generic name (see Art. 32.5).

Ex. 4.  Helleborus niger, Brassica nigra, Verbascum nigrum; Vinca major, Tropaeolum majus; Rubus
amnicola,
the specific epithet being a Latin substantive; Peridermium balsameum Peck, but also
Gloeosporium balsameae J. J. Davis, both derived from the epithet of Abies balsamea, the specific
epithet of which is treated as a substantive in the second example.

23.6.  The following are not to be regarded as specific epithets:

(a)  Words not intended as epithets.

Ex. 5.  Viola qualis Krocker (Fl. Siles. 2: 512, 517. 1790); Urtica dubia? Forsskål (Fl. Aegypt.
-Arab. cxxi. 1775), the word ‘dubia’ being repeatedly used in that work for species which could not
be reliably identified.

Ex. 6.  Atriplex ‘nova’ Winterl (Index Horti Bot. Univ. Pest. fol. A. 8, recto et verso. 1788), the word
nova’ being here used in connection with four different species of Atriplex.

Ex. 7.  However, in Artemisia nova A. Nelson (Bull. Torrey Bot. Club 27: 274. 1900), nova was
intended as a specific epithet, the species having been newly distinguished from others.

(b)  Ordinal adjectives used for enumeration.

Ex. 8.  Boletus vicesimus sextus, Agaricus octogesimus nonus.

(c)  Epithets published in works in which the Linnaean system of binary nomen-
      clature for species is not consistently employed. Linnaeus is regarded as
      having used binary nomenclature for species consistently from 1753 on-
      wards, although there are exceptions, e.g. Apocynum fol. androsaemi L. (Sp.
      Pl. 213. 1753 ≡ Apocynum androsaemifolium L. Sp. Pl. ed. 2. 311. 1762).

Ex. 9.  The name Abutilon album Hill (Brit. Herb. 49. 1756) is a descriptive phrase reduced to two
words, not a binary name in accordance with the Linnaean system, and is to be rejected: Hill’s other
species was Abutilon flore flavo.

Ex. 10.  Secretan (Mycographie Suisse. 1833) introduced a large number of new specific names, more
than half of them not binomials, e.g. Agaricus albus corticis, Boletus testaceus scaber, Boletus aereus
carne lutea
. He is therefore considered not to have consistently used the Linnaean system of binary
nomenclature and none of the specific names, even those with a single epithet, in this work are validly
published.

Ex. 11.  Other works in which the Linnaean system of binary nomenclature is not consistently
employed: Gilibert (Fl. Lit. Inch. 1781; Exerc. Phyt. 1792), Miller (Gard. Dict. Abr. ed. 4. 1754), W.
Kramer (Elench. Veg. 1756).

(d)  Formulae designating hybrids (see Art. H.10.3).

Recommendation 23A

23A.1.  Names of men and women and also of countries and localities used as specific epithets should
be in the form of substantives in the genitive (clusii, porsildiorum, saharae) or of adjectives (clusianus,
dahuricus
) (see also Art. 73, Recs. 73C and D).

 
 

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Infraspecific taxa 24

23A.2.  The use of the genitive and the adjectival form of the same word to designate two different
species of the same genus should be avoided (e.g. Lysimachia hemsleyana Oliver and L. hemsleyi
Franchet).

Recommendation 23B

23B.1.  In forming specific epithets, authors should comply also with the following suggestions:

(a)  To use Latin terminations insofar as possible.

(b)  To avoid epithets which are very long and difficult to pronounce in Latin.

(c)  Not to make epithets by combining words from different languages.

(d)  To avoid those formed of two or more hyphened words.

(e)  To avoid those which have the same meaning as the generic name (pleonasm).

(f)  To avoid those which express a character common to all or nearly all the species of a genus.

(g)  To avoid in the same genus those which are very much alike, especially those which differ only in
       their last letters or in the arrangement of two letters.

(h)  To avoid those which have been used before in any closely allied genus.

(i)   Not to adopt unpublished names found in correspondence, travellers’ notes, herbarium labels, or
       similar sources, attributing them to their authors, unless these authors have approved publica-
       tion.

(j)   To avoid using the names of little-known or very restricted localities, unless the species is quite
       local.

S E C T I O N  5 .  N A M E S  O F  T A X A  B E L O W  T H E  R A N K  O F  S P E C I E S

( I N F R A S P E C I F I C  T A X A )

Article 24

24.1.  The name of an infraspecific taxon is a combination of the name of a
species and an infraspecific epithet connected by a term denoting its rank.

Ex. 1.  Saxifraga aizoon subforma surculosa Engler & Irmscher. This can also be cited as Saxifraga
aizoon
var. aizoon subvar. brevifolia forma multicaulis subforma surculosa Engler & Irmscher; in this
way a full classification of the subforma within the species is given.

24.2.  Infraspecific epithets are formed as those of species and, when adjectival in
form and not used as substantives, they agree grammatically with the generic
name (see Art. 32.5).

Ex. 2.  Trifolium stellatum forma nanum (not nana).

24.3.  Infraspecific epithets such as typicus, originalis, originarius, genuinus, ve-
rus,
and veridicus, purporting to indicate the taxon containing the nomenclatural
type of the next higher taxon, are inadmissible and cannot be validly published
except where they repeat the specific epithet because Art. 26 requires their use.

24.4.  The use of a binary combination instead of an infraspecific epithet is not
admissible. Contrary to Art. 32.1(b), names so constructed are validly published
but
are to be altered to the proper form without change of the author’s name or
date of publication
.

 

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25–26 Infraspecific taxa

Ex. 3.  ‘Salvia grandiflora subsp. S. willeana’ Holmboe is to be cited as Salvia grandiflora subsp.
willeana Holmboe.

Ex. 4.  ‘Phyllerpa prolifera var. Ph. firma’ Kütz. is to be altered to Phyllerpa prolifera var. firma
Kütz.

24.5.  Infraspecific taxa within different species may bear the same epithets; those
within one species may bear the same epithets as other species (but see Rec. 24B).

Ex. 5.  Rosa jundzillii var. leioclada and Rosa glutinosa var. leioclada; Viola tricolor var. hirta in spite
of the previous existence of a different species named Viola hirta.

Note 1.  The use within the same species of the same epithet for infraspecific taxa, even if they are of
different rank, based on different types is illegitimate under Art. 64.3.

Recommendation 24A

24A.1.  Recommendations made for specific epithets (Recs. 23A, B) apply equally to infraspecific
epithets.

Recommendation 24B

24B.1.  Authors proposing new infraspecific epithets should avoid those previously used for species
in the same genus.

Article 25

25.1.  For nomenclatural purposes, a species or any taxon below the rank of
species is regarded as the sum of its subordinate taxa, if any. In fungi, a
holomorph (see Art. 59.4) also includes its correlated form-taxa.

Ex. 1.  When Montia parvifolia (DC.) Greene is treated as containing two subspecies, the name M.
parvifolia
applies to the sum of these subordinate taxa. Under this taxonomic treatment, one must
write M. parvifolia (DC.) Greene subsp. parvifolia if only that part of M. parvifolia which includes its
nomenclatural type and excludes the type of the name of the other subspecies (M. parvifolia subsp.
flagellaris (Bong.) Ferris) is meant.

Article 26

26.1.  The name of any infraspecific taxon that includes the type of the adopted,
legitimate
name of the species to which it is assigned is to repeat the specific
epithet unaltered as its final epithet, but not followed by an author’s name (see
Art. 46). Such names are termed autonyms (Art. 6.8; see also Art. 7.18).

Ex. 1.  The combination Lobelia spicata var. originalis McVaugh, applying to a taxon which includes
the type of the name Lobelia spicata Lam., is to be replaced by Lobelia spicata Lam. var. spicata.

Note 1.  This provision applies only to the names of those subordinate taxa that include the type of
the adopted name of the species (but see Rec. 26A).

26.2.  The first valid publication of a name of an infraspecific taxon that does not
include the type of the adopted, legitimate name of the species automatically
establishes the corresponding autonym (see also Arts. 32.6 and 57.3).

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Cultivated plants 27–28

Ex. 2.  The publication of the name Lycopodium inundatum var. bigelovii Tuckerman (1843) auto-
matica established the name of another variety, Lycopodium inundatum L. var. inundatum, the type
of which is that of the name Lycopodium inundatum L.

Ex. 3.  Utricularia stellaris L. f. (1781) includes U. stellaris var. coromandeliana A. DC. (1844) and U.
stellaris
L. f. var. stellaris (1844) automatically established at the same time. When U. stellaris is
included in U. inflexa Forsskål (1775) as a variety the correct name of the variety, under Art. 57.3, is
U. inflexa var. stellaris (L. f.) P. Taylor (1961).

Recommendation 26A

26A.1.  A variety including the type of the correct name of a subspecies, but not including the type of
the correct name of the species, should, where there is no obstacle under the rules, be given a name
with
the same epithet and type as the subspecies name.

26A.2.  A subspecies not including the type of the correct name of the species should, where there is
no obstacle under the rules, be given a name with the same epithet and type as a name of one of its
subordinate varieties.

26A.3.  A taxon of lower rank than variety which includes the type of the correct name of a subspecies
or variety, but not the type of the correct name of the species, should, where there is no obstacle under
the rules, be given a name with the same epithet and type as the name of the subspecies or variety. On
the other hand, a subspecies or variety which does not include the type of the correct name of the
species should not be given a name with the same epithet as the name of one of its subordinate taxa
below the rank of variety.

Ex. 1.  Fernald treated Stachys palustris subsp. pilosa (Nutt.) Epling as composed of five varieties, for
one of which (that including the type of subsp. pilosa) he made the combination S. palustris var. pilosa
(Nutt.) Fern., there being no legitimate varietal name available.

Ex. 2.  There being no legitimate name available at the rank of subspecies, Bonaparte made the
combination Pteridium aquilinum subsp. caudatum (L.) Bonap., using the same epithet that Sadebeck
had used earlier in the combination P. aquilinum var. caudatum (L.) Sadeb. (both names based on
Pteris caudata L.). Each name is legitimate, and both can be used, as by Tryon, who treated P.
aquilinum
var. caudatum as one of four varieties under subsp. caudatum.

Article 27

27.1.  The final epithet in the name of an infraspecific taxon may not repeat
unchanged the epithet of the correct name of the species to which the taxon is
assigned except when the two names have the same type.

S E C T I O N  6 .  N A M E S  O F  P L A N T S  I N  C U L T I V A T I O N

Article 28

28.1.  Plants brought from the wild into cultivation retain the names that are
applied to the same taxa growing in nature.

28.2.  Hybrids, including those arising in cultivation, may receive names as
provided in Appendix I (see also Arts. 40, and 50).

Note 1.  Additional, independent designations for plants used in agriculture, forestry, and horticul-

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28 Cultivated plants

ture (and arising either in nature or cultivation) are dealt with in the International Code of
Nomenclature for Cultivated Plants, where regulations are provided for their formation and use.
However, nothing precludes the use for cultivated plants of names published in accordance with the
requirements of the International Code of Botanical Nomenclature.

Note 2.  Epithets published in conformity with the International Code of Botanical Nomenclature
may be used as cultivar epithets under the rules of the International Code of Nomenclature for
Cultivated Plants, when this is considered to be the appropriate status for the groups concerned.
Otherwise, cultivar epithets published on or after 1 January 1959 in conformity with the Internation-
al Code of Nomenclature for Cultivated Plants are required to be fancy names markedly different
from epithets of names in Latin form governed by the International Code of Botanical Nomenclature
(see that Code, Art. 27).

Ex. 1.  Cultivar names: Taxus baccata ‘Variegata’ or Taxus baccata cv. Variegata (based on T.
baccata
var. variegata Weston), Phlox drummondii ‘Sternenzauber’, Viburnum  × bodnantense
‘Dawn’.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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Effective publication 29

 
 
 
 
 
 

C H A P T E R  I V .  E F F E C T I V E  A N D  V A L I D  P U B L I C A T I O N

S E C T I O N  1 .  C O N D I T I O N S  A N D  D A T E S  O F  E F F E C T I V E  P U B L I C A T I O N

Article 29

29.1.  Publication is effected, under this Code, only by distribution of printed
matter (through sale, exchange, or gift) to the general public or at least to
botanical institutions with libraries accessible to botanists generally. It is not
effected by communication of new names at a public meeting, by the placing of
names in collections or gardens open to the public, or by the issue of microfilm
made from manuscripts, type-scripts or other unpublished material.

Ex. 1.  Cusson announced his establishment of the genus Physospermum in a memoir read at the
Société des Sciences de Montpellier in 1770, and later in 1782 or 1783 at the Société de Médecine de
Paris, but its effective publication dates from 1787 in the Mémoires de la Société Royale de Médecine
de Paris 5(1): 279.

29.2.  Offer for sale of printed matter that does not exist does not constitute
effective publication.

29.3.  Publication by indelible autograph before 1 Jan. 1953 is effective.

Ex. 2.  Salvia oxyodon Webb & Heldr. was effectively published in July 1850 in an autograph
catalogue placed on sale (Webb & Heldreich, Catalogus Plantarum Hispanicarum . . . ab A. Blanco
lectarum. Paris, July 1850, folio).

Ex. 3.  H. Léveillé, Flore du Kouy Tchéou (1914–1915), a work lithographed from the handwritten
manuscript, is effectively published.

29.4.  For the purpose of this Article, handwritten material, even though repro-
duced by some mechanical or graphic process (such as lithography, offset, or
metallic etching), is still considered as autographic.

29.5.  Publication on or after 1 Jan. 1953 in tradesmen’s catalogues or non-
scientific newspapers, and on or after 1 Jan. 1973 in seed-exchange lists, does not
constitute effective publication.

Recommendation 29A

29A.1.  It is strongly recommended that authors avoid publishing new names and descriptions of new

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30–32 Valid publication

taxa in ephemeral printed matter of any kind, in particular that which is multiplied in restricted and
uncertain numbers, where the permanence of the text may be limited, where the effective publication
in terms of number of copies is not obvious, or where the printed matter is unlikely to reach the
general public. Authors should also avoid publishing new names and descriptions in popular
periodicals, in abstracting journals, or on correction slips.

Article 30

30.1.  The date of effective publication is the date on which the printed matter
became available as defined in Art. 29. In the absence of proof establishing some
other date, the one appearing in the printed matter must be accepted as correct.

Ex. 1.  Individual parts of Willdenow’s Species Plantarum were published as follows: 1(1), 1797; 1(2),
1798; 2(1), 1799; 2(2), 1799 or January 1800; 3(1) (to page 850), 1800; 3(2) (to page 1470), 1802; 3(3)
(to page 2409), 1803 (and later than Michaux’s Flora Boreali-Americana); 4(1) (to page 630), 1805;
4(2), 1806; these dates, which are partly in disagreement with those on the title-pages of the volumes,
are accepted as the correct dates of effective publication.

30.2.  When separates from periodicals or other works placed on sale are issued
in advance, the date on the separate is accepted as the date of effective publica-
tion unless there is evidence that it is erroneous.

Ex. 2.  Publication in separates issued in advance: the names of the Selaginella species published by
Hieronymus in Hedwigia 51: 241-272 (1912) were effectively published on 15 Oct. 1911, since the
volume in which the paper appeared states (p. ii) that the separate appeared on that date.

Recommendation 30A

30A.1.  The date on which the publisher or his agent delivers printed matter to one of the usual
carriers for distribution to the public should be accepted as its date of effective publication.

Article 31

31.1.  The distribution on or after 1 Jan. 1953 of printed matter accompanying
exsiccata does not constitute effective publication.

Note 1.   If the printed matter is also distributed independently of the exsiccata, this constitutes
effective publication.

Ex. 1.  Works such as Schedae operis. . .plantae finlandiae exsiccatae, Helsingfors 1. 1906, 2. 1916, 3.
1933, 1944, or Lundell & Nannfeldt, Fungi exsiccati suecici etc., Uppsala 1-. . ., 1934-. . ., distributed
independently of the exsiccata, whether published before or after 1 Jan. 1953, are effectively
published.

S E C T I O N  2  .  C O N D I T I O N S  A N D  D A T E S  O F  V A L I D  P U B L I C A T I O N  O F  N A M E S

Article 32

32.1.  In order to be validly published, a name of a taxon (autonyms excepted)
must (a) be effectively published (see Art. 29) on or after the starting-point date
of the respective group (Art.
13.1); (b) have a form which complies with the

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Valid publication 32

provisions of Arts. 1627 and Arts. H.67; (c) be accompanied by a description
or diagnosis or by a reference (direct or indirect) to a previously and effectively
published description or diagnosis (except as provided in Art. H.9); and (d)
comply with the special provisions of Arts. 3345.

Ex. 1.  Egeria Néraud (in Gaudichaud, Voy. Uranie, Bot. 25, 28. 1826), published without a
description or a diagnosis or a reference to a former one, was not validly published.

Ex. 2.  The name Loranthus macrosolen Steudel originally appeared without a description or diagno-
sis on the printed tickets issued about the year 1843 with Sect. II. no. 529, 1288, of Schimper’s
herbarium specimens of Abyssinian plants; it was not validly published, however, until A. Richard
(Tent. Pl. Abyss. 1: 340. 1847) supplied a description.

32.2.  A name validly published by reference to a previously and effectively
published description or diagnosis is to be typified by an element selected from
the context of the validating description or diagnosis.

Ex. 3.  Since the name Adenanthera bicolor Moon (1824) is validated solely by reference to Rum-
phius, Herbarium Amboinense 3: t. 112, the type of the name, in the absence of the specimen from
which it was figured, is the illustration referred to. It is not the specimen, at Kew, collected by Moon
and labelled ‘Adenanthera bicolor’.

32.3.  A diagnosis of a taxon is a statement of that which in the opinion of its
author distinguishes the taxon from others.

32.4.  An indirect reference is a clear indication, by the citation of the author’s
name or in some other way, that a previously and effectively published descrip-
tion or diagnosis applies.

Ex. 4.  Kratzmannia Opiz (in Berchtold & Opiz, Oekon.-Techn. Fl. Böhm. 1/2: 398. 1836) is publish-
ed with a diagnosis, but it was not definitely accepted by the author and is therefore not validly
published. It is accepted definitely in Opiz (Seznam 56. 1852), but without any description or
diagnosis. The citation of ‘Kratzmannia O.’ includes an indirect reference to the previously published
diagnosis in 1836.

Ex. 5.  Opiz published the name of the genus Hemisphace (Bentham) Opiz (1852) without a descrip-
tion or diagnosis, but as he wrote Hemisphace Benth. he indirectly referred to the previously
effectively published description by Bentham (Labiat. Gen. Spec. 193. 1833) of Salvia sect. Hemi-
sphace
.

Ex. 6.  The new combination Cymbopogon martini (Roxb.) W. Watson (1882) is validated by the
addition of the number ‘309’, which, as explained at the top of the same page, is the running-number
of the species (Andropogon martini Roxb.) in Steudel (Syn. Pl. Glum. 1: 388. 1854). Although the
reference to the basionym Andropogon martini is indirect, it is perfectly unambiguous.

32.5.  Names published with an incorrect Latin termination but otherwise in
accordance with this Code are regarded as validly published; they are to be
changed to accord with Arts. 1719, 21, 23, and 24, without change of the
author’s name or date of publication.

32.6.  Autonyms (Art. 6.8) are accepted as validly published names, dating from
the publication in which they were established (see Arts. 19.4, 22.2, 26.2),
whether or not they appear in print in that publication.

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33 Valid publication

Note 1.  In certain circumstances an illustration with analysis is accepted as equivalent to a descrip-
tion (see Arts. 42 and 44).

Note 2.  For names of plant taxa that were originally not treated as plants, see Art. 45.

Recommendation 32A

32A.1.  A name should not be validated solely by a reference to a description or diagnosis published
before 1753.

Recommendation 32B

32B.1.  The description or diagnosis of any new taxon should mention the points in which the taxon
differs from its allies.

Recommendation 32C

32C.1.  Authors should avoid adoption of a name which has been previously but not validly
published for a different taxon.

Recommendation 32D

32D.1.  In describing new taxa, authors should, when possible, supply figures with details of structure
as an aid to identification.

32D.2.  In the explanation of the figures, it is valuable to indicate the specimen(s) on which they are
based.

32D.3.  Authors should indicate clearly and precisely the scale of the figures which they publish.

Recommendation 32E

32E.1.  The description or diagnosis of parasitic plants should always be followed by an indication of
the hosts, especially those of parasitic fungi. The hosts should be designated by their scientific names
and not solely by names in modern languages, the applications of which are often doubtful.

Article 33

33.1.  A combination (autonyms excepted) is not validly published unless the
author definitely indicates that the epithet or epithets concerned are to be used in
that particular combination.

Ex. 1.  In Linnaeus’s Species Plantarum the placing of the epithet in the margin opposite the name of
the genus clearly indicates the combination intended. The same result is attained in Miller’s
Gardeners Dictionary, ed. 8, by the inclusion of the epithet in parentheses immediately after the name
of the genus, in Steudel’s Nomenclator Botanicus by the arrangement of the epithets in a list headed
by the name of the genus, and in general by any typographical device which indicates that an epithet is
associated with a particular generic or specific name.

Ex. 2.  Rafinesque’s statement under Blephilia that ‘Le type de ce genre est la Monarda ciliata Linn.’
(J. Phys. Chim. Hist. Nat. Arts 89: 98. 1819) does not constitute publication of the combination
Blephilia ciliata, since he did not indicate that that combination was to be used. Similarly, the
combination Eulophus peucedanoides is not to be ascribed to Bentham on the basis of the listing of
Cnidium peucedanoides, H. B. et K. under Eulophus (in Bentham & Hooker, Gen. Pl. 1: 885. 1867).

33.2.  A new combination, or an avowed substitute (nomen novum), published on
or after 1 Jan. 1953, for a previously and validly published name is not validly
published unless its basionym (name-bringing or epithet-bringing synonym) or

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Valid publication 33

the replaced synonym (when a new name is proposed) is clearly indicated and a
full and direct reference given to its author and place of valid publication with
page or plate reference and date. Bibliographic errors of citation do not invali-
date publication of a new combination.

Ex. 3.  In transferring Ectocarpus mucronatus Saund. to Giffordia, Kjeldsen & Phinney (Madroño 22:
90. 27 Apr. 1973) cited the basionym and its author but without reference to its place of valid
publication. They later (Madroño 22: 154. 2 Jul. 1973) validated the binomial Giffordia mucronata
(Saund.) Kjeldsen & Phinney by giving a full and direct reference to the place of valid publication of
the basionym.

Ex. 4.  Aronia arbutifolia var. nigra (Willd.) Seymour (1969) was published as a new combination
‘Based on Mespilus arbutifolia L. var. nigra Willd., in Sp. Pl. 2: 1013. 1800.’ Willdenow treated these
plants in the genus Pyrus, not Mespilus, and publication was in 1799, not 1800; these errors are
treated as bibliographic errors of citation and do not invalidate the new combination.

Ex. 5.  The combination Trichipteris kalbreyeri was proposed by Tryon (Contr. Gray Herb. 200: 45.
1970) with a full and direct reference to Alsophila kalbreyeri C. Chr. (Index Filic. 44. 1905). This,
however, was not the place of valid publication of the basionym, which had previously been
published, with the same type, by Baker (Summ. New Ferns 9. 1892). Tryon’s bibliographic error of
citation does not invalidate this new combination, which is to be cited as Trichipteris kalbreyeri
(Baker) Tryon.

Ex. 6.  The combination Lasiobelonium corticale was proposed by Raitviir (1980) with a full and
direct reference to Peziza corticalis Fr. (Syst. Mycol. 2: 96. 1822). This, however, was not the place of
valid publication of the basionym, which, under the Code operating in 1980, was in Mérat (Nouv. Fl.
Env. Paris ed. 2, 1: 22. 1821), and under the present Code is in Persoon (Obs. Mycol. 1: 28. 1796).
Raitviir’s bibliographic error of citation does not invalidate the new combination, which is to be cited
as Lasiobelonium corticale (Pers.) Raitviir.

33.3.  Mere reference to the Index Kewensis, the Index of Fungi, or any work
other than that in which the name was validly published does not constitute a full
and direct reference to the original publication of a name.

Note 1.  The publication of a name for a taxon previously known under a misapplied name must be
valid under Arts. 3245. This procedure is not the same as publishing an avowed substitute (nomen
novum
) for a validly published but illegitimate name (Art. 72.1(b)), the type of which is necessarily the
same as that of the name which it replaced (Art. 7.9).

Ex. 7.  Sadleria hillebrandii Robinson (1913) was introduced as a ‘nom. nov.’ for Sadleria pallida
Hilleb. Fl. Haw. Is. 582. 1888. Not Hook. & Arn. Bot. Beech. 75. 1832.’ Since the requirements of
Arts. 3245 were satisfied (for valid publication prior to 1935, simple reference to a previous
description in any language is sufficient), the name is validly published. It is, however, to be
considered the name of a new species, validated by the citation of the misapplication of S. pallida
Hooker & Arn. by Hillebrand, and not a nomen novum as stated; hence, Art. 7.9 does not apply.

Ex. 8.  Juncus bufonius var. occidentalis F. J. Herm. (U.S. Forest Serv. Techn. Rep. RM-18: 14. 1975)
was published as a ‘nom. et stat. nov.’ for J. sphaerocarpus ‘auct. Am., non Nees’. Since there is no
Latin diagnosis nor designation of type, nor reference to any previous publication providing these
requirements, the name is not validly published.

33.4.  A name given to a taxon whose rank is at the same time denoted by a
misplaced term (one contrary to Art. 5) is treated as not validly published,

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34 Valid publication

examples of such misplacement being a form divided into varieties, a species
containing genera, or a genus containing families or tribes.

Ex. 9.  The names tribus Involuta Huth and tribus Brevipedunculata Huth (Bot. Jahrb. Syst. 20: 365,
368. 1895) are not validly published, since Huth misapplied the term ‘tribus’ to a category of lower
rank than section, within the genus Delphinium.

Ex. 10.  Gandoger, in his Flora Europae (1883–1891), applied the term species (‘espèce’) and used
binary nomenclature for two categories of taxa of consecutive rank, the higher rank being equivalent
to that of species in contemporary literature. He misapplied the term species to the lower rank and the
names of these taxa (‘Gandoger’s microspecies’) are not validly published.

33.5.  An exception to Art. 33.4 is made for names of the subdivisions of genera
termed tribes (tribus) in Fries’s Systema Mycologicum, which are treated as
validly published names of subdivisions of genera.

Ex. 11.  Agaricus tribus Pholiota Fr. (1821) is a validly published basionym for the generic name
Pholiota (Fr.) P. Kummer (1871).

Article 34

34.1.  A name is not validly published (a) when it is not accepted by the author in
the original publication; (b) when it is merely proposed in anticipation of the
future acceptance of the group concerned, or of a particular circumscription,
position, or rank of the group (so-called provisional name); (c) when it is merely
mentioned incidentally; (d) when it is merely cited as a synonym; (e) by the mere
mention of the subordinate taxa included in the taxon concerned.

34.2.  Art. 34.1(a) does not apply to names published with a question mark or
other indication of taxonomic doubt, yet published and accepted by the author.
Art. 34.1 (b) does not apply to names for anamorphs of fungi published in
holomorphic genera in anticipation of the discovery of a particular kind of
teleomorph (see Art. 59, Ex. 2).

34.3.  By ‘incidental mention’ of a new name or combination is meant mention
by an author who does not intend to introduce the new name or combination
concerned.

Ex. 1.  (a) The name of the monotypic genus Sebertia Pierre (ms.) was not validly published by
Baillon (Bull. Mens. Soc. Linn. Paris 2: 945. 1891) because he did not accept it. Although he gave a
description of the taxon, he referred its only species Sebertia acuminata Pierre (ms.) to the genus
Sersalisia R. Br. as Sersalisia ? acuminata; under the provision of Art. 34.2 this combination is validly
published. The name Sebertia Pierre (ms.) was later validly published by Engler (1897).

Ex. 2.  (a) The names listed in the left-hand column of the Linnaean thesis Herbarium Amboinense
defended by Stickman (1754) were not accepted by Linnaeus upon publication and are not validly
published.

Ex. 3.  (a) (b) The generic name Conophyton Haw., suggested by Haworth (Rev. Pl. Succ. 82. 1821)
for Mesembryanthemum sect. Minima Haw. (Rev. Pl. Succ. 81. 1821) in the words ‘If this section
proves to be a genus, the name of Conophyton would be apt’, was not validly published, since
Haworth did not adopt that generic name nor accept that genus. The correct name for the genus is
Conophytum N. E. Br. (1922).

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Valid publicatio 34

Ex. 4.  (d) Acosmus Desv. (in Desf., Cat. Pl. Horti Paris. 233. 1829), cited as a synonym of the generic
name Aspicarpa Rich., was not validly published thereby.

Ex. 5.  (d) Ornithogalum undulatum hort. Bouch. (in Kunth, Enum. Pl. 4: 348. 1843), cited as a
synonym under Myogalum boucheanum Kunth, was not validly published thereby; when transferred
to Ornithogalum, this species is to be called O. boucheanum (Kunth) Ascherson (1866).

Ex. 6.  (d) Erythrina micropteryx Poeppig was not validly published by being cited as a synonym of
Micropteryx poeppigiana Walp. (1850); the species concerned, when placed under Erythrina, is to be
called E. poeppigiana (Walp.) Cook (1901).

Ex. 7.  (e) The family name Rhaptopetalaceae Pierre (Bull. Mens. Soc. Linn. Paris 2: 1296. May
1897), which was accompanied merely by mention of constituent genera, Brazzeia, Scytopetalum,
and Rhaptopetalum, was not validly published, as Pierre gave no description or diagnosis; the family
bears the later name Scytopetalaceae Engler (Oct. 1897), which was accompanied by a description.

Ex. 8.  (e) The generic name Ibidium Salisb. (Trans. Hort. Soc. London 1: 291. 1812) was published
merely with the mention of four included species. As Salisbury supplied no generic description or
diagnosis, his Ibidium is not validly published.

34.4.  When, on or after 1 Jan. 1953, two or more different names (so-called
alternative names) are proposed simultaneously for the same taxon by the same
author, none of them is validly published. This rule does not apply in those cases
where the same combination is simultaneously used at different ranks, either for
an infraspecific taxon within a species or for a subdivision of a genus within a
genus (see Recs. 22A.12, 26A.13).

Ex. 9.  The species of Brosimum described by Ducke (Arch. Jard. Bot. Rio de Janeiro 3: 23–29. 1922)
were published with alternative names under Piratinera added in a footnote (pp. 23–24). The
publication of these names, being effected before 1 Jan. 1953, is valid.

Ex. 10.  Euphorbia jaroslavii Polj. (Bot. Mater. Gerb. Bot. Inst. Komarova Akad. Nauk SSSR 15:
155. tab. 1953) was published with an alternative name, Tithymalus jaroslavii. Neither name was
validly published. However, one of the names, Euphorbia yaroslavii (with a different transliteration of
the initial letter), was validly published by Poljakov (1961), who effectively published it with a new
reference to the earlier publication and simultaneously rejected the other name.

Ex. 11.  Description of ‘Malvastrum bicuspidatum subsp. tumidum S. R. Hill var. tumidum, subsp. et
var. nov.’ (Brittonia 32: 474. 1980) simultaneously validated both M. bicuspidatum subsp. tumidum S.
R. Hill and M. bicuspidatum var. tumidum S. R. Hill.

Note 1.   The name of a fungal holomorph and that of a correlated anamorph (see Art. 59), even if
validated simultaneously, are not alternative names in the sense of Art. 34.4. They have different
types and do not pertain to the same taxon: the circumscription of the holomorph is considered to
include the anamorph, but not vice versa.

Ex. 12.  Lasiosphaeria elinorae Linder (1929), the name of a fungal holomorph, and the
simultaneously published name of a correlated anamorph, Helicosporium elinorae Linder, are both
valid, and both can be used under Art. 59.5.

Recommendation 34A

34A.1.  Authors should avoid publishing or mentioning in their publications unpublished names
which they do not accept, especially if the persons responsible for these names have not formally
authorized their publication (see Rec. 23B.1(i)).

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35–36 Valid publication

Article 35

35.1.  A new name or combination published on or after 1 Jan. 1953 without a
clear indication of the rank of the taxon concerned is not validly published.

35.2.  A new name or combination published before 1 Jan. 1953 without a clear
indication of rank is validly published provided that all other requirements for
valid publication are fulfilled; it is, however, inoperative in questions of priority
except for homonymy (see Art. 64.4). If it is a new name, it may serve as a
basionym or replaced synonym for subsequent combinations or avowed substi-
tutes in definite ranks.

Ex. 1.  The groups Soldanellae, Sepincoli, Occidentales, etc., were published without any indication
of rank under the genus Convolvulus by House (Muhlenbergia 4: 50. 1908). These names are validly
published but they are not in any definite rank and have no status in questions of priority except that
they may act as homonyms.

Ex. 2.  In the genus Carex, the epithet Scirpinae was published for an infrageneric taxon of no stated
rank by Tuckerman (Enum. Caric. 8. 1843); this was assigned sectional rank by Kükenthal (in
Engler, Pflanzenr. 38 (IV.20): 81. 1909) and if recognized at this rank is to be cited as Carex sect.
Scirpinae (Tuckerman) Kükenthal.

35.3.  If in a given publication prior to 1 Jan. 1890 only one infraspecific rank is
admitted it is considered to be that of variety unless this would be contrary to the
statements of the author himself in the same publication.

35.4.  In questions of indication of rank, all publications appearing under the
same title and by the same author, such as different parts of a Flora issued at
different times (but not different editions of the same work), must be considered
as a whole, and any statement made therein designating the rank of taxa included
in the work must be considered as if it had been published together with the first
instalment.

Article 36

36.1.  In order to be validly published, a name of a new taxon of plants, the algae
and all fossils excepted, published on or after 1 Jan. 1935 must be accompanied
by a Latin description or diagnosis or by a reference to a previously and
effectively published Latin description or diagnosis (but see Art. H. 9).

Ex. 1.  The names Schiedea gregoriana Degener (Fl. Hawaiiensis, fam. 119. 1936, Apr. 9) and S.
kealiae
Caum & Hosaka (Occas. Pap. Bernice Pauabi Bishop Mus. 11(23): 3. 1936, Apr. 10) were
proposed for the same plant; the type of the former is a part of the original material of the latter. Since
the name S. gregoriana is not accompanied by a Latin description or diagnosis it is not validly
published; the later S. kealiae is legitimate.

36.2.  In order to be validly published, a name of a new taxon of non-fossil algae
published on or after 1 Jan. 1958 must be accompanied by a Latin description or
diagnosis or by a reference to a previously and effectively published Latin
description or diagnosis.

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Valid publication 37–40

Recommendation 36A

36A.1.  Authors publishing names of new taxa of non-fossil plants should give or cite a full
description in Latin in addition to the diagnosis.

Article 37

37.1.  Publication on or after 1 Jan. 1958 of the name of a new taxon of the rank
of family or below is valid only when the nomenclatural type is indicated (see
Arts. 710; but see Art. H.9, Note 1 for the names of certain hybrids).

Recommendation 37A

37A.1.  The indication of the nomenclatural type should immediately follow the Latin description or
diagnosis and should be given by the insertion of the Latin word ‘typus’ (or ‘holotypus’, etc.)
immediately before or after the particulars of the type so designated.

Recommendation 37B

37B.1.  When the type of a name of a new taxon is a specimen, the place where it is permanently
conserved should be indicated.

Article 38

38.1.  In order to be validly published, a name of a new taxon of fossil plants of
specific or lower rank published on or after 1 Jan. 1912 must be accompanied by
an illustration or figure showing the essential characters, in addition to the
description or diagnosis, or by a reference to a previously and effectively pub-
lished illustration or figure.

Article 39

39.1.  In order to be validly published, a name of a new taxon of non-fossil algae
of specific or lower rank published on or after 1 Jan. 1958 must be accompanied
by an illustration or figure showing the distinctive morphological features, in
addition to the Latin description or diagnosis, or by a reference to a previously
and effectively published illustration or figure.

Recommendation 39A

39A.1.  The illustration or figure required by Art. 39 should be prepared from actual specimens,
preferably including the holotype.

Article 40

40.1.  In order to be validly published, names of hybrids of specific or lower rank
with Latin epithets must comply with the same rules as names of non-hybrid taxa
of the same rank.

Ex. 1.  The name Nepeta  × faassenii Bergmans (Vaste Pl. ed. 2. 544. 1939) with a description in
Dutch, and in Gentes Herb. 8: 64 (1949) with a description in English, is not validly published, not
being accompanied by or associated with a Latin description or diagnosis. The name
Nepeta  × faassenii Bergmans ex Stearn (1950) is validly published, being accompanied by a Latin
description with designation of type.

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41 Valid publication

Ex. 2.  The name Rheum  × cultorum Thorsrud & Reis. (Norske Plantenavr. 95. 1948), being here a
nomen nudum, is not validly published.

Ex. 3.  The name Fumaria  × salmonii Druce (List Brit. Pl. 4. 1908) is not validly published, because
only its presumed parentage F. densiflora  ×  F. officinalis is stated.

Note 1.  For names of hybrids of the rank of genus or subdivision of a genus, see Art. H. 9

40.2.  For purposes of priority, names in Latin form given to hybrids are subject
to the same rules as are those of non-hybrid taxa of equivalent rank.

Ex. 4.  The name  × Solidaster Wehrh. (1932) antedates the name  × Asterago Everett (1937) for the
hybrid Aster  ×  Solidago.

Ex. 5.  The name  × Gaulnettya W. J. Marchant (1937) antedates the name  × Gaulthettya Camp
(1939) for the hybrid Gaultheria  ×  Pernettya.

Ex. 6.  Anemone  × hybrida Paxton (1848) antedates A.  × elegans Decne. (1852), pro sp., as the
binomial for the hybrids derived from A. hupehensis  ×  A. vitifolia.

Ex. 7.  In 1927, Aimée Camus (Bull. Mus. Hist. Nat. (Paris) 33: 538. 1927) published the name
Agroelymus as the ‘generic’ name of an intergeneric hybrid, without a Latin diagnosis or description,
mentioning only the names of the parents involved (Agropyron and Elymus). Since this name was not
validly published under the Code then in force (Stockholm 1950), Jacques Rousseau, in 1952 (Mém.
Jard. Bot. Montréal 29: 10-11), published a Latin diagnosis. However, the date of valid publication of
the name  × Agroelymus under this Code (Art. H. 9) is 1927, not 1952, and the name also antedates
× Elymopyrum Cugnac (Bull. Soc. Hist. Nat. Ardennes 33: 14. 1938) which is accompanied by a
statement of parentage and a description in French but not Latin.

Article 41

41.1.  In order to be validly published, a name of a family must be accompanied
(a) by a description or diagnosis of the
family, or (b) by a reference (direct or
indirect) to a previously and effectively published description or diagnosis of
a
family or subdivision of a family.

41.2.  In order to be validly published, a name of a genus must be accompanied
(a) by a description or diagnosis of the genus (but see Art. 42), or (b) by a
reference (direct or indirect) to a previously and effectively published description
or diagnosis of a genus or subdivision of a genus.

Ex. 1.  Validly published generic names: Carphalea A. L. Juss., accompanied by a generic descrip-
tion; Thuspeinanta T. Durand, accompanied by a reference to the previously described genus
Tapeinanthus Boiss. (non Herbert); Aspalathoides (DC.) K. Koch, based on a previously described
section, Anthyllis sect. Aspalathoides DC.; Scirpoides Scheuchzer ex Séguier (Pl. Veron. Suppl. 73.
1754), accepted there but without a generic description, validated by indirect reference (through the
title of the book and a general statement in the preface) to the generic diagnosis and further direct
references in Séguier (Pl. Veron. 1: 117. 1745).

Note 1.  An exception to Art. 41.2 is made for the generic names first published by Linnaeus in
Species Plantarum ed. 1 (1753) and ed. 2 (1762–1763), which are treated as having been validly
published on those dates (see Art. 13.4).

Note 2.  In certain circumstances, an illustration with analysis is accepted as equivalent to a generic
description (see Art. 42.2).

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Valid publication 42–43

Article 42

42.1.  The names of a genus and a species may be simultaneously validated by
provision of a single
description (descriptio generico-specifica) or diagnosis, even
though this may have been intended as only generic or specific, if all of the
following conditions obtain: (a) the genus is at that time monotypic; (b) no
other names (at any rank) have previously been validly published based on the
same type; and (c) the names of the genus and species otherwise fulfil the
requirements for valid publication. Reference to an earlier description or diagno-
sis is not accepted as provision of such a description or diagnosis.

Note 1.   In this context a monotypic genus is one for which a single binomial is validly published,
even though the author may indicate that other species are attributable to the genus.

Ex. 1.  Strophioblachia fimbriicalyx Boerl. is a new species without separate definition, assigned to
the monotypic new genus Strophioblachia. Both names are validly published with a combined generic
and specific description.

Ex. 2.  Piptolepis phillyreoides Bentham is a new species assigned to the monotypic new genus
Piptolepis published with a combined generic and specific description.

Ex. 3.  In publishing the name Phaelypea without a generic description P. Browne (Civ. Nat. Hist.
Jamaica 269. 1756) included and described a single species, but he gave the species a phrase-name and
did not provide a valid binomial. Art. 42 does not therefore apply and the name Phaelypea is not
validly published.

42.2.  Prior to 1 Jan. 1908 an illustration with analysis, or for non-vascular plants
a single figure showing details aiding identification, is acceptable, for the purpose
of this Article, in place of a written description or diagnosis.

Note 2.   An analysis in this context is a figure or group of figures, commonly separate from the main
illustration of the plant (though usually on the same page or plate), showing details aiding identifica-
tion, with or without a separate caption.

Ex. 4.  The generic name Philgamia Baillon (1894) was validly published, as it appeared on a plate
with analysis of the only included species, P. hibbertioides Baillon, and was published before 1 Jan.
1908.

Article 43

43.1.  A name of a taxon below the rank of genus is not validly published unless
the name of the genus or species to which it is assigned is validly published at the
same time or was validly published previously.

Ex. 1.  Suaeda baccata, S. vera, and names for four other species of Suaeda were published with
diagnoses and descriptions by Forsskål (Fl. Aegypt.-Arab. 69–71. 1775), but he provided no
diagnosis or description for the genus: these specific names were therefore, like the generic name, not
validly published by him.

Ex. 2.  In 1880, Müller Argoviensis (Flora 63: 286) published the new genus Phlyctidia with the
species P. hampeana n. sp., P. boliviensis (= Phlyctis boliviensis Nyl.), P. sorediiformis (= Phlyctis
sorediiformis
Kremp.), P. brasiliensis (= Phlyctis brasiliensis Nyl.), and P. andensis (= Phlyctis

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44–45 Valid publication

andensis Nyl.). These specific names are, however, not validly published in this place, because the
generic name Phlyctidia was not validly published; Müller gave no generic description or diagnosis
but only a description and a diagnosis of the new species P. hampeana. This description and diagnosis
cannot validate the generic name as a descriptio generico-specifica under Art. 42 since the new genus
was not monotypic. Valid publication of the name Phlyctidia was by Müller (1895), who provided a
short generic diagnosis. The only species mentioned here were P. ludoviciensis n. sp. and P. boliviensis
(Nyl.). The latter combination was validly published in 1895 by the reference to the basionym.

Note 1.   This Article applies also to specific and other epithets published under words not to be
regarded as generic names (see Art. 20.4).

Ex. 3.  The binary combination Anonymos aquatica Walter (Fl. Carol. 230. 1788) is not validly
published. The correct name for the species concerned is Planera aquatica J. F. Gmelin (1791), and
the date of the name, for purposes of priority, is 1791. The species must not be cited as Planera
aquatica
(Walter) J. F. Gmelin.

Ex. 4.  The binary combination Scirpoides paradoxus Rottb. (Descr. Pl. Rar. Progr. 27. 1772) is not
validly published since Scirpoides in this context is a word not intended as a generic name. The first
validly published name for this species is Fuirena umbellata Rottb. (1773).

Article 44

44.1.  The name of a species or of an infraspecific taxon published before 1 Jan
1908 is validly published if it is accompanied only by an illustration with analysis
(see Art. 42, Note 2).

Ex. 1.  Panax nossibiensis Drake (1896) was validly published on a plate with analysis.

44.2.  Single figures of non-vascular plants showing details aiding identification
are considered as illustrations with analysis (see Art. 42, Note 2).

Ex. 2.  Eunotia gibbosa Grunow (1881), a name of a diatom, was validly published by provision of a
single figure of the valve.

Article 45

45.1.  The date of a name is that of its valid publication. When the various
conditions for valid publication are not simultaneously fulfilled, the date is that
on which the last is fulfilled. However, the name must always be explicitly
accepted in the place of its validation. A name published on or after 1 Jan. 1973
for which the various conditions for valid publication are not simultaneously
fulfilled is not validly published unless a full and direct reference is given to the
places where these requirements were previously fulfilled.

Ex. 1.  The name Clypeola minor was first published in the Linnaean thesis Flora Monspeliensis
(1756), in a list of names preceded by numerals but without an explanation of the meaning of these
numerals and without any other descriptive matter; when the thesis was reprinted in vol. 4 of the
Amoenitates Academicae (1759), a statement was added explaining that the numbers referred to
earlier descriptions published in Magnol’s Botanicon Monspeliense. However, the name Clypeola
minor
was absent from the reprint, being no longer accepted by Linnaeus, and is not therefore validly
published.

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Valid publication 45

Ex. 2.  Alyssum gionae was one of several new species published by Quézel & Contandriopoulos
(Naturalia Monspel. Sér. Bot. 16: 89–149. 1965) with a Latin diagnosis but without citation of a type.
Later (Taxon 16: 240. 1967) they designated a type specimen for that name, accompanied by a
reference to the earlier description and diagnosis. Although this reference was not full and direct,
lacking the page number, Alyssum gionae Quézel & Contandr. was, in 1967, validly published.

45.2.  A correction of the original spelling of a name (see Art. 73) does not affect
its date of valid publication.

Ex. 3.  The correction of the orthographic error in Gluta benghas L. (Mant. 293. 1771) to Gluta
renghas
L. does not affect the date of publication of the name even though the correction dates only
from 1883 (Engler in A. DC. & C. DC., Monogr. Phan. 4: 225).

45.3.  For purposes of priority only legitimate names are taken into considera-
tion (see Arts. 11, 6367). However, validly published earlier homonyms, whe-
ther legitimate or not, shall cause rejection of their later homonyms (unless the
latter are conserved).

45.4.  If a taxon originally assigned to a group not covered by this Code is treated
as belonging to a group of plants other than algae, the authorship and date of any
of its names are determined by the first publication that satisfies the requirements
for valid publication under this Code. If the taxon is treated as belonging to the
algae, any of its names need satisfy only the requirements of the pertinent non-
botanical code for status equivalent to valid publication under the botanical
Code (but see Art. 65, regarding homonymy).

Ex. 4.  Amphiprora Ehrenb. (1843) is an available* name for a genus of animals first treated as
belonging to the a
lgae by Kützing (1844). Amphiprora has priority in botanical nomenclature from
1843, not 1844.

Ex. 5.  Petalodinium J. Cachon & M. Cachon (Protistologica 5: 16. 1969) is available under the
International Code of Zoological Nomenclature as the name of a genus of dinoflagellates. When the
taxon is treated as belonging to the algae, its name retains its original authorship and date even
though the original publication lacked a Latin diagnosis.

Ex. 6.  Labyrinthodyction Valkanov (Progr. Protozool. 3: 373. 1969), although available under the
International Code of Zoological Nomenclature as the name of a genus of rhizopods, is not valid
when the taxon is treated as belonging to the fungi because the original publication lacked a Latin
diagnosis.

Ex. 7.  Protodiniferidae Kofoid & Swezy (Mem. Univ. Calif. 5: 111. 1921), available under the
International Code of Zoological Nomenclature, is validly published as a name of a family of algae
with its original authorship and date but with the termination -idae changed to -aceae (in accordance
with Arts. 18.4 and 32.5).

Recommendation 45A

45A.1.  Authors using new names in works written in a modern language (floras, catalogues, etc.)
should simultaneously comply with the requirements of valid publication.

 

*  The word ‘available’ in the International Code of Zoological Nomenclature is equivalent to
‘validly published’ in the International Code of Botanical Nomenclature.

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46 Citation

Recommendation 45B

45B.1.  Authors should indicate precisely the dates of publication of their works. In a work appearing
in parts the last-published sheet of the volume should indicate the precise dates on which the different
fascicles or parts of the volume were published as well as the number of pages and plates in each.

Recommendation 45C

45C.1.  On separately printed and issued copies of works published in a periodical, the name of the
periodical, the number of its volume or parts, the original pagination, and the date (year, month, and
day)
should be indicated.

S E C T I O N  3 .  C I T A T I O N  O F  A U T H O R S ’  N A M E S  A N D  O F  L I T E R A T U R E  F O R

P U R P O S E S  O F  P R E C I S I O N

Article 46

46.1.  For the indication of the name of a taxon to be accurate and complete, and
in order that the date may be readily verified, it is necessary to cite the name of the
author(s) who validly published the name concerned unless the provisions for
autonyms apply (Arts. 19.3, 22.1, and 26.1; see also Art. 16.1).

Ex. 1.  Rosaceae A. L. Juss., Rosa L., Rosa gallica L., Rosa gallica var. eriostyla R. Keller, Rosa
gallica
L. var. gallica.

Recommendation 46A

46A.1.  Authors’ names put after names of plants may be abbreviated, unless they are very short. For
this purpose, particles are suppressed unless they are an inseparable part of the name, and the first
letters are given without any omission (Lam. for J. B. P. A. Monet Chevalier de Lamarck, but De
Wild. for E. De Wildeman).

46A.2.  If a name of one syllable is long enough to make it worth while to abridge it, the first
consonants only are given (Fr. for Elias Magnus Fries); if the name has two or more syllables, the first
syllable and the first letter of the following one are taken, or the two first when both are consonants
(Juss. for Jussieu, Rich. for Richard).

46A.3.  When it is necessary to give more of a name to avoid confusion between names beginning
with the same syllable, the same system is to be followed. For instance, two syllables are given
together with the one or two first consonants of the third; or one of the last characteristic consonants
of the name is added (Bertol. for Bertoloni, to distinguish it from Bertero; Michx. for Michaux, to
distinguish it from Micheli).

46A.4.  Given names or accessory designations serving to distinguish two botanists of the same name
are abridged in the same way (Adr. Juss. for Adrien de Jussieu, Gaertner f. for Gaertner filius, J. F.
Gmelin for Johann Friedrich Gmelin, J. G. Gmelin for Johann Georg Gmelin, C. C. Gmelin for Carl
Christian Gmelin, S. G. Gmelin for Samuel Gottlieb Gmelin, Müll. Arg. for Jean Müller of Aargau).

46A.5.  When it is a well-established custom to abridge a name in another manner, it is best to
conform to it (L. for Linnaeus, DC. for de Candolle, St.-Hil. for Saint-Hilaire, R. Br. for Robert
Brown).

Recommendation 46B

46B.1.  In citing the author of the scientific name of a taxon, the romanization of the author’s name(s)
given in the original publication should normally be accepted. Where an author failed to give a
romanization, or where an author has at different times used different romanizations, then the

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Citation 46

romanization known to be preferred by the author or that most frequently adopted by the author
should be accepted. In the absence of such information the author’s name should be romanized in
accordance with an internationally available standard.

46B.2  Authors of scientific names whose personal names are not written in Roman letters should
romanize their names, preferably (but not necessarily) in accordance with an internationally avail-
able standard and, as a matter of typographic convenience, without diacritical signs. Once authors
have selected the romanization of their personal names, they should use it consistently thereafter.
Whenever possible, authors should not permit editors or publishers to change the romanization of
their personal names.

Recommendation 46C

46C.1.  When a name has been published jointly by two authors, the names of both should be cited,
linked by means of the word et or by an ampersand (&).

Ex. 1.  Didymopanax gleasonii Britton et Wilson (or Britton & Wilson).

46C.2.  When a name has been published jointly by more than two authors, the citation should be
restricted to that of the first one followed by et al.’

Ex. 2.  Lapeirousia erythrantha var. welwitschii (Baker) Geerinck, Lisowski, Malaisse & Symoens
(Bull. Soc. Roy. Bot. Belgique 105: 336. 1972) should be cited as L. erythrantha var. welwitschii
(Baker) Geerinck et al.

Recommendation 46D

46D.1.  When a name with a description or diagnosis (or reference to a description or diagnosis)
supplied by one author is published in a work by another author, the word in should be used to
connect the names of the two authors. In such cases the name of the author who supplied the
description or diagnosis is the most important and should be retained when it is desirable to
abbreviate such a citation.

Ex. 1.  Viburnum ternatum Rehder in Sargent, Trees and Shrubs 2: 37 (1907), or V. ternatum Rehder;
Teucrium charidemi Sandw. in Lacaita, Cavanillesia 3: 38 (1930), or T. charidemi Sandw.

Recommendation 46E

46E.1.  When an author who validly publishes a name ascribes it to another person, the correct
author citation is the name of the actual publishing author, but the name of the other person,
followed by the connecting word ex, may be inserted before the name of the publishing author, if
desired. The same holds for names of garden origin ascribed to ‘hort.’ (hortulanorum).

Ex. 1.  Gossypium tomentosum Seemann or G. tomentosum Nutt. ex Seemann; Lithocarpus polysta-
chyus
(A. DC.) Rehder or L. polystachyus (Wall. ex A. DC.) Rehder; Orchis rotundifolia Pursh or O.
rotundifolia
Banks ex Pursh; Carex stipata Willd. or C. stipata Muhlenb. ex Willd.; Gesneria donklarii
Hooker or G. donklarii hort. ex Hooker.

46E.2.  When an author who validly publishes a name ascribes it to an author who published the
name before the starting point of the group concerned (see Art. 13.1), the author citation may
include, when such indication is considered useful or desirable, the name of the pre-starting-point
author followed by ex as in Rec. 46E.1.

Ex. 2.  Lupinus L. or Lupinus Tourn. ex L.; Euastrum binale Ralfs or E. binale Ehrenb. ex Ralfs.

Recommendation 46F

46F.1.  Authors of new names of taxa should not use the expression nobis (nob.) or a similar
reference to themselves as an author citation but should cite their own names in each instance.

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47–49 Citation

Article 47

47.1.  An alteration of the diagnostic characters or of the circumscription of a
taxon without the exclusion of the type does not warrant the citation of the name
of an author other than the one who first published its name.

Examples: see under Art. 51.

Recommendation 47A

47A.1.  When an alteration as mentioned in Art. 47 has been considerable, the nature of the change
may be indicated by adding such words, abbreviated where suitable, as emendavit (emend.)
(followed by the name of the author responsible for the change), mutatis characteribus (mut. char.).
pro parte (p.p.), excluso genere or exclusis generibus (excl. gen.), exclusa specie or exclusis
speciebus
(excl. sp.), exclusa varietate or exclusis varietatibus (excl. var.), sensu amplo (s. ampl.).
sensu stricto (s. str.), etc.

Ex. 1.  Phyllanthus L. emend. Müll. Arg.; Globularia cordifolia L. excl. var. (emend. Lam.).

Article 48

48.1.  When an author adopts an existing name but explicitly excludes its original
type, he is considered to have published a later homonym that must be ascribed
solely to him. Similarly, when an author who adopts a name refers to an apparent
basionym but explicitly excludes its type, he is considered to have published a
new name that must be ascribed solely to him. Explicit exclusion can be effected
by simultaneous explicit inclusion of the type in a different taxon by the same
author (see also Art. 59.6).

Ex. 1.  Sirodot (1872) placed the type of Lemanea Bory (1808) in Sacheria Sirodot (1872); hence
Lemanea, as treated by Sirodot (1872), is to be cited as Lemanea Sirodot non Bory and not as
Lemanea Bory emend. Sirodot.

Ex. 2.  The name Amorphophallus campanulatus, published by Decaisne, was apparently based on
Arum campanulatum Roxb. However, the type of the latter was explicitly excluded by Decaisne, and
the name is to be cited as Amorphophallus campanulatus Decne., not as Amorphophallus campanulatus
(Roxb.) Decne.

Note 1.   Misapplication of a new combination to a different taxon, but without explicit exclusion of
the type of the basionym, is dealt with under Arts. 55.2 and 56.2.

Note 2.  Retention of a name in a sense that excludes the type can be effected only by conservation
(see Art. 14.8).

Article 49

49.1.  When a genus or a taxon of lower rank is altered in rank but retains its
name or epithet, the author of the earlier, epithet-bringing legitimate name (the
author of the basionym) must be cited in parentheses, followed by the name of
the author who effected the alteration (the author of the new name). The same
holds when a taxon of lower rank than genus is transferred to another genus or
species, with or without alteration of rank.

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Citation 50

Ex. 1.  Medicago polymorpha var. orbicularis L. when raised to the rank of species becomes Medicago
orbicularis
(L.) Bartal.

Ex. 2.  Anthyllis sect. Aspalathoides DC. raised to generic rank, retaining the epithet Aspalathoides as
its name, is cited as Aspalathoides (DC.) K. Koch.

Ex. 3.  Cineraria sect. Eriopappus Dumort. (Fl. Belg. 65. 1827) when transferred to Tephroseris
(Reichenb.) Reichenb. is cited as Tephroseris sect. Eriopappus (Dumort.) Holub (Folia Geobot.
Phytotax. Bohem. 8: 173. 1973).

Ex. 4.  Cistus aegyptiacus L. when transferred to Helianthemum Miller is cited as Helianthemum
aegyptiacum
(L.) Miller.

Ex. 5.  Fumaria bulbosa var. solida L. (1753) was elevated to specific rank as F. solida (L.) Miller
(
1771). The name of this species when transferred to Corydalis is to be cited as C. solida (L.) Clairv.
(1811), not
C. solida (Miller) Clairv.

Ex. 6.  However, Pulsatilla montana var. serbica W. Zimmerm. (Feddes Repert. Spec. Nov. Regni
Veg.
61: 95. 1958), originally placed under P. montana subsp. australis (Heuffel) Zam., retains the
same author citation when placed under P. montana subsp. dacica Rummelsp. (see Art. 24.1) and is
not cited as var. serbica (W. Zimmerm.) Rummelsp. (Feddes Repert. 71: 29. 1965).

Ex. 7.  Salix subsect. Myrtilloides C. Schneider (Ill. Handb. Laubholzk. 1: 63. 1904), originally
placed under S. sect. Argenteae Koch, retains the same author citation when placed under S. sect.
Glaucae Pax and is not cited as S. subsect. Myrtilloides (C. Schneider) Dorn (Canad. J. Bot. 54: 2777.
1976).

Article 50

50.1.  When the status of a taxon at the rank of species or below is altered to the
hybrid category (nothotaxon, see Art. H.3) of corresponding rank (Art. H.10.2),
or vice versa, the name of the original author is cited and may be followed by an
indication in parentheses of the original status. Subsequently, and if the context
appears to permit it, the indication of original status may be omitted.

Ex. 1.  Stachys ambigua Smith was published as a species. If regarded as a hybrid, it is cited as Stachys
× ambigua Smith (pro sp.).

Ex. 2.  The binary name Salix  × glaucops Andersson was published as the name of a hybrid. Later,
Rydberg (Bull. New York Bot. Gard. 1: 270. 1899) altered the status of the taxon to that of a species.
If this view is accepted, the name is cited as Salix glaucops Andersson (pro hybr.).

S E C T I O N  4 .  G E N E R A L  R E C O M M E N D A T I O N S  O N  C I T A T I O N

Recommendation 50A

50A.1.  In the citation of a name published as a synonym, the words ‘as synonym’ or pro syn. should
be added.

50A.2.  When an author has published as a synonym a manuscript name of another author, the word
ex should be used in citations to connect the names of the two authors (see Rec. 46E.1).

Ex. 1.  Myrtus serratus, a manuscript name of Koenig published by Steudel as a synonym of Eugenia
laurina
Willd., should be cited thus: Myrtus serratus Koenig ex Steudel, pro syn.

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50 Citation

Recommendation 50B

50B.1.  In the citation of a nomen nudum, its status should be indicated by adding the words nomen
nudum
’ or ‘nom. nud.

Ex. 1.  Carex bebbii Olney (Car. Bor.-Am. 2: 12. 1871), published without a diagnosis or description,
should be cited as a nomen nudum.

Recommendation 50C

50C.1.  The citation of a later homonym should be followed by the name of the author of the earlier
homonym preceded by the word non, preferably with the date of publication added. In some
instances it will be advisable to cite also any other homonyms, preceded by the word nec.

Ex. 1.  Ulmus racemosa Thomas, Amer. J. Sci. Arts 19: 170 (1831), non Borkh. 1800; Lindera Thunb,
Nov. Gen. Pl. 64 (1783), non Adanson 1763; Bartlingia Brongn., Ann. Sci. Nat. (Paris) 10: 373 (1821)
non Reichenb. 1824 nec F. Muell. 1882.

Recommendation 50D

50D.1.  Misidentifications should not be included in synonymies but added after them. A misapplied
name should be indicated by the words auct. non followed by the name of the original author and
the bibliographic reference of the misidentification.

Ex. 1.  Ficus stortophylla Warb. in Warb. & De Wild., Ann. Mus. Congo Belge, B, Bot. ser. 4, 1: 32
(1904). F. irumuensis De Wild., Pl. Bequaert. 1: 341 (1922). F. exasperata auct. non Vahl: De Wild. et
T. Durand, Ann. Mus. Congo Belge, B, Bot. ser. 2, 1: 54 (1899); De Wild., Miss. Em. Laurent 26
(1905); T. Durand & H. Durand, Syll. Fl. Congol. 505 (1909).

Recommendation 50E

50E.1.  If a generic or specific name is accepted as a nomen conservandum (see Art. 14 and App. III)
the abbreviation nom. cons. should be added to the citation.

Ex. 1.  Protea L., Mant. Pl. 187 (1771), nom. cons., non L. 1753; Combretum Loefl. (1758), nom.
cons.
(syn. prius Grislea L. 1753).

50E.2.  If it is desirable to indicate the sanctioned status of the names of fungi adopted by Persoon or
Fries (see Art. 13.1(d)), ‘: Pers.’ or ‘: Fr.’ should be added to the citation.

Ex. 2.  Boletus piperatus Bull. : Fr.

Recommendation 50F

50F.1.  Except as provided in Art. 75, a name cited in synonymy should be spelled exactly as
published by its author. If any explanatory words are required, these should be inserted in brackets. If
a name is adopted with alterations from the form as originally published, it is desirable that in full
citations the exact original form should be added, preferably between quotation marks.

Ex. 1.  Pyrus calleryana Decne. (Pyrus mairei H. Léveillé, Repert. Spec. Nov. Regni Veg. 12: 189.
1913, Pirus’).

Ex. 2.  Zanthoxylum cribrosum Sprengel, Syst. Veg. 1: 946 (1825), Xanthoxylon. (Zanthoxylum
caribaeum
var. floridanum (Nutt.) A. Gray, Proc. Amer. Acad. Arts 23: 225. 1888, Xanthoxylum).

Ex. 3.  Spathiphyllum solomonense Nicolson, Amer. J. Bot. 54: 496 (1967), ‘solomonensis’.

 
 
 

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Transference of taxa 51–52

 
 
 
 
 
 

C H A P T E R  V. R E T E N T I O N ,  C H O I C E ,  A N D  R E J E C T I O N  O F 

N A M E S  A N D  E P I T H E T S

S E C T I O N  1.   R E T E N T I O N  O F  N A M E S  O R  E P I T H E T S  W H E N  T A X A A R E

R E M O D E L L E D  O R  D I V I D E D

Article 51

51.1.  An alteration of the diagnostic characters or of the circumscription of a
taxon does not warrant a change in its name, except as may be required (a) by
transference of the taxon (Arts. 5456), or (b) by its union with another taxon of
the same rank (Arts. 57, 58), or (c) by a change of its rank (Art. 60).

Ex. 1.  The genus Myosotis as revised by R. Brown differs from the original genus of Linnaeus, but
the generic name has not been changed, nor is a change allowable, since the type of Myosotis L.
remains in the genus; it is cited as Myosotis L. or as Myosotis L. emend. R. Br. (see Art. 47, Rec. 47A).

Ex. 2.  Various authors have united with Centaurea jacea L. one or two species which Linnaeus had
kept distinct; the taxon so constituted is called Centaurea jacea L. sensu amplo or Centaurea jacea L.
emend. Cosson & Germ., emend. Vis., or emend. Godron, etc.; any new name for this taxon, such as
Centaurea vulgaris Godron, is superfluous and illegitimate.

51.2.  An exception to Art. 51.1 is made for the family name Papilionaceae (see
Art. 18.5).

Article 52

52.1.  When a genus is divided into two or more genera, the generic name, if
correct,
must be retained for one of them. If a type was originally designated the
generic name must be retained for the genus including that type. If no type has
been designated, a type must be chosen (see Guide for the determination of types,
p. 79).

Ex. 1.  The genus Dicera Forster & Forster f. was divided by Rafinesque into the two genera Misipus
and Skidanthera. This procedure is contrary to the rules: the name Dicera must be kept for one of the
genera, and it is now retained for that part of Dicera including the lectotype, D. dentata.

Ex. 2.  Among the sections which have been recognized in the genus Aesculus L. are Aesculus sect.
Aesculus, sect. Pavia (Miller) Walp., sect. Macrothyrsus (Spach) K. Koch, and sect. Calothyrsus
(Spach) K. Koch, the last three of which were regarded as distinct genera by the authors cited in
parentheses. In the event of these four sections being treated as genera, the name Aesculus must be
kept for the first of them, which includes Aesculus hippocastanum L., the type of the generic name.

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53–55 Transference of taxa

Article 53

53.1.  When a species is divided into two or more species, the specific name, if
correct,
must be retained for one of them. If a particular specimen, description,
or figure was originally designated as the type, the specific name must be retained
for the species including that element. If no type has been designated, a type must
be chosen (see Guide for the determination of types, p. 79).

Ex. 1.  Arabis beckwithii S. Watson (1887) was based on specimens which represented at least two
species in the opinion of Munz, who based A. shockleyi Munz (1932) on one of the specimens cited by
Watson, retaining the name A. beckwithii for the others (one of which may be designated as lectotype
of A. beckwithii).

Ex. 2.  Hemerocallis lilioasphodelus L. (1753) was originally treated by Linnaeus as consisting of two
varieties: var. flava (flavus) and var. fulva (fulvus). In 1762 he recognized these as distinct species,
calling them H. flava and H. fulva. The original specific epithet was reinstated for one of these by
Farwell (Amer. Midl. Naturalist 11: 51. 1928) and the two species are correctly named H. lilioaspho-
delus
L. and H. fulva (L.) L.

53.2.  The same rule applies to infraspecific taxa, for example, to a subspecies
divided into two or more subspecies, or to a variety divided into two or more
varieties.

S E C T I O N  2 .  R E T E N T I O N  O F  E P I T H E T S  O F  T A X A  B E L O W  T H E  R A N K  O F 

G E N U S  O N  T R A N S F E R E N C E  T O  A N O T H E R  G E N U S  O R  S P E C I E S

Article 54

54.1.  When a subdivision of a genus is transferred to another genus or placed
under another generic name for the same genus without change of rank, the
epithet of its formerly correct name must be retained unless one of the following
obstacles exists:

(a)  The resulting combination has been previously and validly published for a
      subdivision of a genus based on a different type;

(b)  The epithet of an earlier legitimate name of the same rank is available (but
      see Arts. 13.1(d), 58, 59);

(c)  Arts. 21 or 22 provide that another epithet be used.

Ex. 1.  Saponaria sect. Vaccaria DC. when transferred to Gypsophila becomes Gypsophila sect.
Vaccaria (DC.) Godron.

Ex. 2.  Primula sect. Dionysiopsis Pax (1909) when transferred to the genus Dionysia becomes
Dionysia sect. Dionysiopsis (Pax) Melchior (1943); the name Dionysia sect. Ariadne Wendelbo (1959),
based on the same type, is not to be used.

Article 55

55.1.  When a species is transferred to another genus or placed under another
generic name for the same genus without change of rank, the epithet of its

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Transference of taxa 55

formerly correct name must be retained unless one of the following obstacles
exists:

(a)  The resulting binary name is a later homonym (Art. 64) or a tautonym (Art.
      23.4);

(b)  The epithet of an earlier legitimate specific name is available (but see Arts.
      13.1(d), 58, 59).
 

Ex. 1.  Antirrhinum spurium L. (1753) when transferred to the genus Linaria must be called Linaria
spuria
(L.) Miller (1768).

Ex. 2.  Spergula stricta Sw. (1799) when transferred to the genus Arenaria must be called Arenaria
uliginosa
Schleicher ex Schlechtendal (1808) because of the existence of the name Arenaria stricta
Michx. (1803), referring to a different species; but on further transfer to the genus Minuartia the
epithet stricta must be used and the species called Minuartia stricta (Sw.) Hiern (1899).

Ex. 3.  Conyza candida L. (1753) was illegitimately renamed Conyza limonifolia Smith (1813) and
Inula limonifolia Boiss. (1843). However, the Linnaean epithet must be retained and the correct name
of the species, in the genus Inula, is I. candida (L.) Cass. (1822).

Ex. 4.   When transferring Serratula chamaepeuce L. (1753) to his new genus Ptilostemon, Cassini
renamed the species P. muticus Cass. (1826, ‘muticum’). Lessing rightly reinstated the original specific
epithet, creating the combination Ptilostemon chamaepeuce (L.) Less. (1832).

Ex. 5.  Spartium biflorum Desf. (1798) when transferred to the genus Cytisus by Spach in 1849 could
not be called C. biflorus, because this name had been previously and validly published for a different
species by L’Héritier in 1791; the name C. fontanesii given by Spach is therefore legitimate.

Ex. 6.  Arum dracunculus L. (1753) when transferred to the genus Dracunculus was renamed Dracun-
culus vulgaris
Schott (1832), as use of the Linnaean epithet would create a tautonym
.

Ex. 7.  Melissa calamintha L. (1753) when transferred to the genus Thymus becomes T. calamintha
(L.) Scop. (1772); placed in the genus Calamintha it may not be called C. calamintha (a tautonym) but
has been named C. officinalis Moench (1794). However, when C. officinalis is transferred to the genus
Satureja, the Linnaean epithet is again available and the name becomes S. calamintha (L.) Scheele
(1843).

Ex. 8.  Cucubalus behen L. (1753) was legitimately renamed Behen vulgaris Moench (1794) to avoid
the tautonym Behen behen. If the species is transferred to the genus Silene, it may not retain its
original epithet because of the existence of a Silene behen L. (1753). Therefore, the substitute name
Silene cucubalus Wibel (1799) was created. However, the specific epithet vulgaris was still available
under Silene. It was rightly reinstated in the combination Silene vulgaris (Moench) Garcke (1869).

55.2.  On transference of a specific epithet under another generic name, the
resulting combination must be retained for the species to which the type of the
basionym belongs, and
attributed to the author who first published it, even
though it may have
been applied erroneously to a different species (Art. 7.10; but
see Arts.
48.1 and 59.6).

Ex. 9.  Pinus mertensiana Bong. was transferred to the genus Tsuga by Carrière, who, however, as is
evident from his description, erroneously applied the new combination Tsuga mertensiana to another
species of Tsuga, namely T. heterophylla (Raf.) Sarg. The combination Tsuga mertensiana (Bong.)
Carrière must not be applied to T. heterophylla (Raf.) Sarg. but must be retained for Pinus
mertensiana
Bong. when that species is placed in Tsuga; the citation in parentheses (under Art. 49) of
the name of the original author, Bongard, indicates the type of the name.

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56–57 Union of taxa

Article 56

56.1.  When an infraspecific taxon is transferred without change of rank to
another genus or species, the final epithet of its formerly correct name must be
retained unless one of the following obstacles exists:

(a)  The resulting ternary combination, with a different type, has been previously
      and validly published for an infraspecific taxon of any rank;

(b)  The epithet of an earlier legitimate name at the same rank is available (but see
      Arts. 13.1(d), 58, 59);

(c)  Art. 26 provides that another epithet be used.

Ex. 1.  Helianthemum italicum var. micranthum Gren. & Godron (Fl. France 1: 171. 1847) when
transferred as a variety to H. penicillatum Thibaud ex Dunal retains its varietal epithet, becoming H.
penicillatum
var. micranthum (Gren. & Godron) Grosser (in Engler, Pflanzenr. 14 (IV. 193): 115
1903).

56.2.  On transference of an infraspecific epithet under another specific name, the
resulting combination must be retained for the taxon to which the type of the
basionym belongs, and
attributed to the author who first published it, even
though it may have
been applied erroneously to a different taxon (Art. 7.10; but
see Arts. 48.1 and 59.6).

S E C T I O N  3 .  C H O I C E  O F  N A M E S  W H E N  T A X A  O F  T H E  S A M E  R A N K  A R E

U N I T E D

Article 57

57.1.  When two or more taxa of the same rank are united, the earliest legitimate
name or (for taxa below the rank of genus) the final epithet of the earliest
legitimate name is retained, unless another epithet or a later name must be
accepted under the provisions of Arts. 13.1(d), 14, 16.1, 19.3, 22.1, 26.1, 27, 55.1,
58, or 59.

Ex. 1.  Schumann (in Engler & Prantl, Nat. Pflanzenfam. III, 6: 5. 1890), uniting the three genera
Sloanea L. (1753), Echinocarpus Blume (1825), and Phoenicosperma Miq. (1865), rightly adopted the
earliest of these three generic names, Sloanea L., for the resulting genus.

57.2.  The author who first unites taxa bearing names of equal priority must
choose one of them, unless an autonym is involved (see Art. 57.3). The name he
chooses is then treated as having priority.

Ex. 2.  If the two genera Dentaria L. (1 May 1753) and Cardamine L. (1 May 1753) are united, the
resulting genus must be called Cardamine because that name was chosen by Crantz (Cl. Crucif.
Emend. 126. 1769), who was the first to unite the two genera.

Ex. 3.  R. Brown (in Tuckey, Narr. Exp. Congo 484. 1818) appears to have been the first to unite
Waltheria americana L. (1 May 1753) and W. indica L. (1 May 1753). He adopted the name W. indica
for the combined species, and this name is accordingly to be retained.

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Union of taxa 58

Ex. 4.  Baillon (Adansonia 3: 162. 1863), when uniting for the first time Sclerocroton integerrimus
Hochst. ex Krauss (Flora 28: 85. 1845) and Sclerocroton reticulatus Hochst. ex Krauss (Flora 28: 85.
1845), adopted the epithet integerrimus in the name of the combined taxon. Consequently this epithet
is to be retained irrespective of the generic name (Sclerocroton, Stillingia, Excoecaria, Sapium) with
which it is combined.

Ex. 5.  Linnaeus in 1753 simultaneously published the names Verbesina alba and V. prostrata. Later
(1771), he published Eclipta erecta, a superfluous name because V. alba is cited in synonymy, and E.
prostrata
, based on V. prostrata. The first author to unite these taxa was Roxburgh (Fl. Ind. 3: 438.
1832), who did so under the name Eclipta prostrata (L.) L., which therefore is to be used if these taxa
are united and placed in the genus Eclipta.

Ex. 6.  When the genera Entoloma (Fr. ex Rabenh.) P. Kummer (1871), Leptonia (Fr.) P. Kummer
(1871), Eccilia (Fr.) P. Kummer (1871), Nolonea (Fr.) P. Kummer (1871), and Claudopus Gillet
(1876) are united, one of the generic names simultaneously published by Kummer must be used for
the whole, as was done by Donk (Bull. Jard. Bot. Buitenzorg ser. 3, 18(1): 157. 1949) who selected
Entoloma. The name Rhodophyllus Quélet (1886), introduced to cover these combined genera, is
superfluous.

57.3.  An autonym is treated as having priority over the name or names of the
same date and rank that established it.

Note 1.  When the final epithet of an autonym is used in a new combination under the requirements of
Art. 57.3, the basionym of that combination is the name from which the autonym is derived.

Ex. 7.  Heracleum sibiricum L. (1753) includes H. sibiricum subsp. lecokii (Godron & Gren.) Nyman
(1879) and H. sibiricum subsp. sibiricum (1879) automatically established at the same time. When H.
sibiricum
is included in H. sphondylium L. (1753) as a subspecies, the correct name for the taxon is H.
sphondylium
subsp. sibiricum (L.) Simonkai (1887), not subsp. lecokii.

Ex. 8.  In the classification adopted by Rollins and Shaw, Lesquerella lasiocarpa (Hooker ex A.
Gray) S. Watson is composed of two subspecies, subsp. lasiocarpa (which includes the type of the
name of the species and is cited without an author) and subsp. berlandieri (A. Gray) Rollins & E.
Shaw. The latter subspecies is composed of two varieties. In this classification the correct name of the
variety which includes the type of subsp. berlandieri is L. lasiocarpa var. berlandieri (A. Gray) Payson
(1922), not L. lasiocarpa var. berlandieri (cited without an author) nor L. lasiocarpa var. hispida (S.
Watson) Rollins & E. Shaw (1972), based on Synthlipsis berlandieri var. hispida S. Watson (1882),
since publication of the latter name established the autonym Synthlipsis berlandieri A. Gray var.
berlandieri which, at varietal rank, is treated as having priority over var. hispida
.

Recommendation 57A

57A.1.  Authors who have to choose between two generic names should note the following sugges-
tions:

(a)  Of two names of the same date, to prefer that which was first accompanied by the description of a
      species.

(b)  Of two names of the same date, both accompanied by descriptions of species, to prefer that which,
      when the author makes his choice, includes the larger number of species.

(c)  In cases of equality from these various points of view, to select the more appropriate name.

Article 58

58.1.  When a non-fossil taxon of plants, algae excepted, and a fossil (or subfos-
sil
) taxon of the same rank are united, the correct name of the non-fossil taxon is
treated as having priority (see
Pre.7).

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59 Pleomorphic fungi

Ex. 1.  If Platycarya Siebold & Zucc. (1843), a non-fossil genus, and Petrophiloides Bowerbank
(1840), a fossil genus, are united, the name Platycarya is accepted for the combined genus, although
it is antedated by Petrophiloides.

Ex. 2.  The generic name Metasequoia Mild (1941) was based on the fossil type of M. disticha (Heer)
Miki. After discovery of the non-fossil species M. glyptostroboides Hu & Cheng, conservation of
Metasequoia Hu & Cheng (1948) as based on the non-fossil type was approved. Otherwise, any new
generic name based on M. glyptostroboides would have had to be treated as having priority over
Metasequoia Miki.

S E CT I O N  4.  N A M E S  O F  F U N G I  W I T H  A  P L E O M O R P H I C  L I F E  C Y C L E 

Article 59

59.1.  In ascomycetous and basidiomycetous fungi (including Ustilaginales)
with mitotic asexual morphs (anamorphs) as well as a meiotic sexual morph
(teleomorph), the correct name covering the holomorph (i.e., the species in all its
morphs) is  –  except for lichen-forming fungi  –  the earliest legitimate name
typified by an element representing the teleomorph, i.e. the morph characterized
by the production of asci/ascospores, basidia/basidiospores, teliospores,
or other basidium-bearing organs.

59.2.  For a binary name to qualify as a name of a holomorph, not only must its
type specimen be teleomorphic, but also the protologue must include a diagnosis
or description of this morph (or be so phrased that the possibility of reference to
the teleomorph cannot be excluded).

59.3.  If these requirements are not fulfilled, the name is that of a form-taxon and
is applicable only to the anamorph represented by its type, as described or
referred to in the protologue. The accepted taxonomic disposition of the type of
the name determines the application of the name, no matter whether the genus to
which a subordinate taxon is assigned by the author(s) is holomorphic or
anamorphic.

59.4.  The priority of names of holomorphs at any rank is not affected by the
earlier publication of names of anamorphs judged to be correlated morphs of the
holomorph.

59.5.  The provisions of this article shall not be construed as preventing the
publication and use of binary names for form-taxa when it is thought necessary
or desirable to refer to anamorphs alone.

Note 1.  When not already available, specific or infraspecific names for anamorphs may he proposed
at the time of publication of the name for the holomorphic fungus or later. The epithets may, if
desired, be identical, as long as they are not in homonymous combinations.

59.6.  As long as there is direct and unambiguous evidence for the deliberate
introduction of a new morph judged by the author(s) to be correlated with the
morph typifying a purported basionym, and this evidence is strengthened by

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Change of rank 60

fulfilment of all requirements in Arts. 3245 for valid publication of a name of a
new taxon, any indication such as ‘comb. nov.’ or ‘nom. nov.’ is regarded as a
formal error, and the name introduced is treated as that of a new taxon, and
attributed solely to the author(s) thereof. When only the requirements for valid
publication of a new combination (Arts. 33, 34) have been fulfilled, the name is
accepted as such and based, in accordance with Art. 55, on the type of the
declared or implicit basionym.

Ex. 1.  The name Penicillium brefeldianum Dodge, based on teleomorphic and anamorphic material,
is a valid and legitimate name of a holomorph, in spite of the attribution of the species to a form-
genus. It is legitimately combined in a holomorphic genus as Eupenicillium brefeldianum (Dodge)
Stolk & Scott. P. brefeldianum is not available for use in a restricted sense for the anamorph alone.

Ex. 2.  The name Ravenelia cubensis Arthur & Johnston, based on a specimen bearing only uredinia
(an anamorph), is a valid and legitimate name of an anamorph, in spite of the attribution of the
species to a holomorphic genus. It is legitimately combined in a form-genus as Uredo cubensis
(Arthur & Johnston) Cummins. R. cubensis is not available for use inclusive of the teleomorph.

Ex. 3.  Mycosphaerella aleuritidis was published as (Miyake) Ou comb. nov., syn. Cercospora
aleuritidis
Miyake’ but with a Latin diagnosis of the teleomorph. The indication ‘comb. nov.’ is taken
as a formal error, and M. aleuritidis Ou is accepted as a validly published new specific name for the
holomorph, typified by the teleomorphic material described by Ou.

Ex. 4.  Corticium microsclerotium was published in 1939 as ‘(Matz) Weber, comb. nov., syn. Rhizoc-
tonia microsclerotia
Matz’ with a description, only in English, of the teleomorph. Because of Art. 36,
this may not be considered as the valid publication of the name of a new species, and so C.
microsclerotium (Matz) Weber must be considered a validly published and legitimate new combina-
tion based on the specimen of the anamorph that typifies its basionym. C. microsclerotium Weber, as
published in 1951 with a Latin description and a teleomorphic type, is an illegitimate later homonym
of the combination C. microsclerotium (Matz) Weber (1939), typified by an anamorph.

Ex. 5.  Hypomyces chrysospermus Tul. (Ann. Sci. Nat. Bot. ser. 4, 13: 16. 1860), presented as the
name of a holomorph without the indication ‘comb. nov.’ but with explicit reference to Mucor
chrysospermus
(Bull.) Bull. and Sepedonium chrysospermum (Bull.) Fr., which are names of its
anamorph, is not to be considered as a new combination but as the name of a newly described species,
with a teleomorphic type.

Recommendation 59A

59A.1  When a new morph of a fungus is described, it should be published either as a new taxon (e.g.,
gen. nov., sp. nov., var. nov.) whose name has a teleomorphic type, or as a new anamorph (anam.
nov.) whose name has an anamorphic type.

59A.2  When in naming a new morph of a fungus the epithet of the name of a different, earlier
described morph of the same fungus is used, the new name should be designated as the name of a new
taxon or anamorph, as the case may be, but not as a new combination based on the earlier name.

S E C T I O N  5 .  C H O I C E  O F  N A M E S  W H E N  T H E  R A N K  O F  A  T A X O N  I S  C H A N G E D

Article 60

60.1.  In no case does a name have priority outside its own rank.

Ex. 1.  Campanula sect. Campanopsis R. Br. (Prodr. 561. 1810) as a genus is called Wahlenbergia

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61–62 Rejection

Roth (1821), a name conserved against the taxonomic synonym Cervicina Delile (1813), and not
Campanopsis (R. Br.) Kuntze (1891).

Ex. 2.  Magnolia virginiana var. foetida L. (1753) when raised to specific rank is called Magnolia
grandiflora
L. (1759), not M. foetida (L.) Sarg. (1889).

Ex. 3.  Lythrum intermedium Ledeb. (1822) when treated as a variety of Lythrum salicaria L. (1753)
has been called L. salicaria var. glabrum Ledeb. (Fl. Ross. 2: 127. 1843), and hence may not be called
L. salicaria var. intermedium (Ledeb.) Koehne (Bot. Jahrb. Syst. 1: 327. 1881).

Article 61

61.1.  When a taxon at the rank of family or below is changed to another such
rank, the correct name is the earliest legitimate one available in the new rank.

Recommendation 61A

61A.1.  When a family or subdivision of a family is changed in rank and no earlier legitimate name is
available in the new rank, the stem of the name should be retained and only the termination (-aceae,
-oideae, -eae, -inae) altered, unless the resulting name would be a later homonym.

Ex. 1.  The subtribe Drypetinae Pax (1890) (Euphorbiaceae) when raised to the rank of tribe was
named Drypeteae (Pax) Hurusawa (1954); the subtribe Antidesmatinae Pax (1890) (Euphorbiaceae)
when raised to the rank of subfamily was named Antidesmatoideae (Pax) Hurusawa (1954).

61A.2.  When a section or a subgenus is raised in rank to a genus, or the inverse change occurs, the
original name or epithet should be retained unless the resulting name would be contrary to this Code.

61A.3.  When an infraspecific taxon is raised in rank to a species, or the inverse change occurs, the
original epithet should be retained unless the resulting combination would be contrary to this Code.

61A.4.  When an infraspecific taxon is changed in rank within the species, the original epithet should
be retained unless the resulting combination would be contrary to this Code.

S E C T I O N  6.  R E J E C T I O N  O F  N A M E S  A N D  E P I T H E T S

Article 62

62.1.  An epithet or a legitimate name must not be rejected merely because it is
inappropriate or disagreeable, or because another is preferable or better known
or because it has lost its original meaning, or (in pleomorphic fungi with names
governed by Art. 59) because the generic name does not accord with the morph
represented by its type.

Ex. 1.  The following changes are contrary to the rule: Staphylea to Staphylis, Tamus to Thamnos
Thamnus, or Tamnus, Mentha to Minthe, Tillaea to Tillia, Vincetoxicum to Alexitoxicum; and
Orobanche rapum to O. sarothamnophyta, O. columbariae to O. columbarihaerens, O. artemisiae to O.
artemisiepiphyta
. All these modifications are to be rejected.

Ex. 2.  Ardisia quinquegona Blume (1825) is not to be changed to A. pentagona A. DC. (1834)
although the specific epithet quinquegona is a hybrid word (Latin and Greek) (see Rec. 23B.1(c))

Ex. 3.  The name Scilla peruviana L. is not to be rejected merely because the species does not grow in
Peru.

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Rejection 63

Ex. 4.  The name Petrosimonia oppositifolia (Pallas) Litv., based on Polycnemum oppositifolium
Pallas, is not to be rejected merely because the species has leaves only partly opposite, and partly
alternate, although there is another closely related species, Petrosimonia brachiata (Pallas) Bunge,
having all its leaves opposite.

Ex. 5.  Richardia L. is not to be changed to Richardsonia, as was done by Kunth, although the name
was originally dedicated to the British botanist, Richardson.

62.2.  The names of species and of subdivisions of genera assigned to genera
whose names are conserved later homonyms, and which had earlier been as-
signed to the genera under the rejected homonymic names, are legitimate under
the conserved names without change of authorship or date if there is no other
obstacle under the rules.

Ex. 6.  Alpinia languas J. F. Gmelin (1791) and Alpinia galanga (L.) Willd. (1797) are to be accepted
although Alpinia L. (1753), to which they were assigned by their authors, is rejected and the genus in
which they are now placed is Alpinia Roxb. (1810), nom. cons.

Article 63

63.1.  A name is illegitimate and is to be rejected if it was nomenclaturally
superfluous when published, i.e. if the taxon to which it was applied, as circum-
scribed by its author, included the type of a name which ought to have been
adopted, or whose epithet ought to have been adopted, under the rules (but see
Art. 63.3)
.

Ex. 1.  The generic name Cainito Adanson (1763) is illegitimate because it was a superfluous name for
Chrysophyllum L. (1753) which Adanson cited as a synonym.

Ex. 2.  Chrysophyllum sericeum Salisb. (1796) is illegitimate, being a superfluous name for
C. cainito L. (1753), which Salisbury cited as a synonym.

Ex. 3.  On the other hand, Salix myrsinifolia Salisb. (1796) is legitimate, being explicitly based upon
S. myrsinites of Hoffmann (Hist. Salic. Ill. 71. 1787), a misapplication of the name S. myrsinites L.

Ex. 4.  Picea excelsa Link is illegitimate because it is based on Pinus excelsa Lam. (1778), a
superfluous name for Pinus abies L. (1753). Under Picea the proper name is Picea abies (L.) H
Karsten.

Ex. 5.  On the other hand, Cucubalus latifolius Miller and C. angustifolius Miller (1768) are not
illegitimate names, although these species are now united with the species previously named C. behen
L. (1753): C. latifolius Miller and C. angustifolius Miller as circumscribed by Miller did not include
the type of C. behen L., which name he adopted for another independent species.

63.2.  The inclusion of a type (see Art. 7) is here understood to mean the citation
of the type specimen, the citation of an illustration of the type specimen, the
citation of the type of a name, or the citation of the name itself unless the type is at
the same time excluded either explicitly or by implication.

Ex. 6.  Explicit exclusion of type: When publishing the name Galium tricornutum, Dandy (Watsonia
4: 47. 1957) cited G. tricorne Stokes (1787) pro parte as a synonym, but explicitly excluded the type of
the latter name.

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64 Rejection

Ex. 7.  Exclusion of type by implication: Cedrus Duhamel (1755) is a legitimate name even though
Juniperus L. was cited as a synonym; only some of the species of Juniperus L. were included in Cedrus
and the differences between the two genera are discussed, Juniperus (including its type) being
recognized in the same work as an independent genus.

Ex. 8.  Tmesipteris elongata Dangeard (Botaniste 2: 213. 1890–1891) was published as a new species
but Psilotum truncatum R. Br. was cited as a synonym. However, on the following page (214), T.
truncata
(R. Br.) Desv. is recognized as a different species and on p. 216 the two are distinguished in a
key, thus showing that the meaning of the cited synonym was either P. truncatum R. Br. pro parte’ or
P. truncatum auct. non R. Br.’

Ex. 9.  Solanum torvum Sw. (Prodr. 47. 1788) was published with a new diagnosis but S. indicum
(1753) was cited as a synonym. In accord with the practice in his Prodromus, Swartz indicated where
the species was to be inserted in the latest edition [14, Murray] of the Systema Vegetabilium. S. torvum
was to be inserted between species 26 (S. insanum) and 27 (S. ferox); the number of S. indicum in
edition of the Systema is 32. S. torvum is thus a legitimate name; the type of S. indicum is excluded by
implication.

63.3.  A name that was nomenclaturally superfluous when published is not
illegitimate if its basionym is legitimate, or if it is based on the stem of a legitimate
generic name. When published it is incorrect, but it may become correct later.

Ex. 10.  Chloris radiata (L.) Sw. (1788), based on Agrostis radiata L. (1759), was nomenclaturally
superfluous when published, since Swartz also cited Andropogon fasciculatus L. (1753) as a synonym
It is, however, the correct name in the genus Chloris for Agrostis radiata when Andropogon
fasciculatus
is treated as a different species, as was done by Hackel (in A. DC. & C. DC., Monogr.
Phan. 6: 177. 1889).

Ex. 11.  The generic name Hordelymus (Jessen) Jessen (1885), based on the legitimate Hordeum subg.
Hordelymus Jessen (Deutschl. Gräser 202. 1863), was superfluous when published because its type,
Elymus europaeus L., is also the type of Cuviera Koeler (1802). Cuviera Koeler has since been rejected
in favour of its later homonym Cuviera DC., and Hordelymus (Jessen) Jessen can now be used as a
correct name for the segregate genus containing Elymus europaeus L.

63.4.  A statement of parentage accompanying the publication of a name for a
hybrid cannot make the name superfluous.

Ex. 12.  The name Polypodium  × shivasiae Rothm. (1962) was proposed for hybrids between P.
australe
and P. vulgare subsp. prionodes, while at the same time the author accepted P.  × font-queri
Rothm. (1936) for hybrids between P. australe and P. vulgare subsp. vulgare. Under Art. H.4.1, P
× shivasiae is a synonym of P.  × font-queri; nevertheless, it is not a superfluous name.

Article 64

64.1.  A name, unless conserved (Art. 14) or sanctioned under Art. 13.1(d), is
illegitimate if it is a later homonym, that is, if it is spelled exactly like a name
based on a different type that was previously and validly published for a taxon of
the same rank.

Note 1.  Even if the earlier homonym is illegitimate, or is generally treated as a synonym on
taxonomic grounds, the later homonym must be rejected.
 
 

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Rejection 64

Ex. 1.  The name Tapeinanthus Boiss. ex Bentham (1848), given to a genus of Labiatae, is a later
homonym of Tapeinanthus Herbert (1837), a name previously and validly published for a genus of
Amaryllidaceae; Tapeinanthus Boiss. ex Bentham is therefore rejected, as was done by T. Durand
(1888), who renamed it Thuspeinanta.

Ex. 2.  The generic name Amblyanthera Müll. Arg. (1860) is a later homonym of the validly published
generic name Amblyanthera Blume (1849) and is therefore rejected, although Amblyanthera Blume is
now considered to be a synonym of Osbeckia L. (1753).

Ex. 3.  The name Torreya Arn. (1838) is a nomen conservandum and is therefore not to be rejected
because of the existence of the earlier homonym Torreya Raf. (1818).

Ex. 4.  Astragalus rhizanthus Boiss. (1843) is a later homonym of the validly published name
Astragalus rhizanthus Royle (1835) and it is therefore rejected, as was done by Boissier in 1849, who
renamed it A. cariensis.

64.2.  When two or more generic, specific, or infraspecific names based on
different types
are so similar that they are likely to be confused*, because they are
applied to related taxa or for any other reason, they are to be treated as
homonyms.

Ex. 5.  Names treated as homonyms: Astrostemma Bentham and Asterostemma Decne.; Pleuripeta-
lum
Hooker and Pleuropetalum T. Durand; Eschweilera DC. and Eschweileria Boerl.; Skytanthus
Meyen and Scytanthus Hooker.

Ex. 6.  The three generic names Bradlea Adanson, Bradleja Banks ex Gaertner, and Braddleya Vell.,
all commemorating Richard Bradley, must be treated as homonyms because only one can be used
without serious risk of confusion.

Ex. 7.  Kadalia Raf. and Kadali Adanson (both Melastomataceae) are treated as homonyms (Taxon
15: 287. 1966); Acanthoica Lohmann and Acanthoeca W. Ellis (both flagellates) are sufficiently alike
to be considered homonyms (Taxon 22: 313. 1973); Solanum saltiense S. L. Moore and S. saltense
(Bitter) C. Morton should be treated as homonyms (Taxon 22: 153. 1973).

Ex. 8.  Epithets so similar that they are likely to be confused if combined under the same generic or
specific name
: chinensis and sinensis; ceylanica and zeylanica; napaulensis, nepalensis, and nipalensis;
polyanthemos
and polyanthemus; macrostachys and macrostachyus; heteropus and heteropodus;
poikilantha
and poikilanthes; pteroides and pteroideus; trinervis and trinervius; macrocarpon and
macrocarpum; trachycaulum and trachycaulon.

Ex. 9.  Names not likely to be confused: Rubia L. and Rubus L.; Monochaete Doell and Monochae-
tum
(DC.) Naudin; Peponia Grev. and Peponium Engler; Iria (Pers.) Hedwig and Iris L.; Desmosta-
chys
Miers and Desmostachya (Stapf) Stapf; Symphyostemon Miers and Symphostemon Hiern;
Gerrardina Oliver and Gerardiina Engler; Durvillaea Bory and Urvillea Kunth; Peltophorus Desv.

(Gramineae) and Peltophorum (Vogel) Bentham (Leguminosae); Senecio napaeifolius (DC.) Schultz-
Bip. and S. napifolius MacOwan (the epithets being derived respectively from Napaea and Napus);

Lysimachia hemsleyana Oliver and L. hemsleyi Franchet (see, however, Rec. 23A.2); Euphorbia peplis
L. and E. peplus L.

 

*  When it is doubtful whether names are sufficiently alike to be confused, a request for a decision
may be submitted to the General Committee (see Division III) which will refer it for examination to
the committee or committees for the appropriate taxonomic group or groups. A recommendation
may then be put forward to an International Botanical Congress, and, if ratified, will become a
binding decision. (This provision was adopted in 1981 and none of the examples are yet in the
nature of a binding decision.)

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65 Rejection

Ex. 10.  Acanthococcus Lagerh. (an alga) and Acanthococos Barb. Rodr. (a palm) are not likely to be
confused and should not be treated as homonyms (Taxon 18: 735. 1969).

Ex. 11.  Names conserved against earlier names treated as homonyms (see App. III): Lyngbya
Gomont (vs. Lyngbyea Sommerf.); Columellia Ruiz & Pavón (vs. Columella Lour.), both commemo-
rating Columella, the Roman writer on agriculture; Cephalotus Labill. (vs. Cephalotos Adanson);
Simarouba Aublet (vs. Simaruba Boehmer).

64.3.  The names of two subdivisions of the same genus, or of two infraspecific
taxa within the same species, even if they are of different rank, are treated as
homonyms if they have the same epithet and are not based on the same type. The
same epithet may be used for subdivisions of different genera, and for infraspe-
cific taxa within different species.

Ex. 12.  Verbascum sect. Aulacosperma Murb. (1933) is allowed, although there was already a Celsia
sect. Aulacospermae Murb. (1926). This, however, is not an example to be followed, since it is
contrary to Rec. 21B.2.

Ex. 13.  The names Andropogon sorghum subsp. halepensis (L.) Hackel and A. sorghum var. halepen-
sis
(L.) Hackel (in A. DC & C.DC., Monogr. Phan. 6: 502. 1889) are legitimate, since both have the
same type and the epithet may be repeated under Rec. 26A.1.

Ex. 14.  Anagallis arvensis var. caerulea (L.) Gouan (Fl. Monsp. 30. 1765), based on A. caerulea L
(1759), makes illegitimate the combination A. arvensis subsp. caerulea Hartman (Sv. Norsk Exc.-Fl.
32. 1846), based on the later homonym A. caerulea Schreber (1771).

64.4.  When two or more homonyms have equal priority, the first of them that is
adopted by an author who simultaneously rejects the other(s) is treated as having
priority. Likewise, if an author substitutes
other names for all but one of these
homonyms, the homonym for the taxon that is not renamed is treated as having
priority
.

Ex. 15.  Linnaeus simultaneously published both Mimosa 10 cinerea (Sp. Pl. 517. 1753) and Mimosa
25 cinerea (Sp. Pl. 520.1753). In 1759, he renamed species 10 Mimosa cineraria and retained the
name Mimosa cinerea for species 25; Mimosa cinerea is thus a legitimate name for species 25.

Ex. 16.  Rouy & Foucaud (Fl. France 2: 30. 1895) published the name Erysimum hieraciifolium var.
longisiliquum, with two different types, for two different taxa under different subspecies. Only one of
these names can be maintained.

Article 65

65.1.  Consideration of homonymy does not extend to the names of taxa not
treated as plants, except as stated below:

(a)  Later homonyms of the names of taxa once treated as plants are illegitimate,
      even though the taxa have been reassigned to a different group of organisms
      to which this Code does not apply.

(b)  A name originally published for a taxon other than a plant, even if validly
      published under Arts. 3245 of this Code, is illegitimate if it becomes a
      homonym of a plant name when the taxon to which it applies is first treated
      as a plant (see also Art. 45.4).

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Rejection 66–69

Note 1.  The International Code of Nomenclature of Bacteria provides that a bacterial name is
illegitimate if it is a later homonym of a name of a taxon of bacteria, fungi, algae, protozoa, or viruses.

Article 66

66.1.  A name of a subdivision of a genus is illegitimate and is to be rejected if it
was published in contravention of Arts. 51, 54, 57, 58, or 60, i.e. if its author did
not adopt the epithet of the earliest legitimate name available for the taxon with
its particular circumscription, position, and rank (but see Art. 63.3).

Note 1.  Illegitimate names are not to be taken into consideration for purposes of priority (see Art.
45.3) except in the rejection of a later homonym (Art. 64).

Note 2.  An epithet originally published as part of an illegitimate name may be adopted later for the
same taxon, but in another combination (see Art. 72).

Article 67

67.1.  A specific or infraspecific name is illegitimate and is to be rejected if it was
published in contravention of Arts. 51, 53, 55, 56, or 60, i.e. if its author did not
adopt the final epithet of the earliest legitimate name available for the taxon with
its particular circumscription, position, and rank (but see Art. (but see Art. 63.3).

Note 1.  Illegitimate names are not to be taken into consideration for purposes of priority (see Art.
45.3) except in the rejection of a later homonym (Art. 64).

Note 2.  A final epithet originally published as part of an illegitimate name may be adopted later for
the same taxon, but in another combination (see Art. 72).

Article 68

68.1.  A specific name is not illegitimate merely because its epithet was originally
combined with an illegitimate generic name, but is to be taken into consideration
for purposes of priority if the epithet and the corresponding combination are in
other respects in accordance with the rules.

Ex. 1.  Agathophyllum A. L. Juss. (1789) is an illegitimate generic name, being a superfluous
substitute for Ravensara Sonn. (1782). Nevertheless the validly published name Agathophyllum
neesianum
Blume (1851) is legitimate. Because Meisner cited Agathophyllum neesianum as a synonym
of Mespilodaphne mauritiana Meisner (1864) but did not adopt its epithet, M. mauritiana is a
superfluous name and hence illegitimate.

68.2.  An infraspecific name may be legitimate even if its final epithet was
originally placed under an illegitimate name.

Article 69

69.1.  A name may be ruled as rejected if it has been widely and persistently used
for a taxon or taxa not including its type. A name thus rejected, or its basionym if
 

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70–72 Rejection

it has one, is placed on a list of nomina rejicienda. Along with the listed names, all
combinations based on them are similarly rejected, and none is to be used.

69.2.  The list of rejected names will remain permanently open for additions and
changes. Any proposal of an additional name must be accompanied by a detailed
statement of the cases both for and against its rejection. Such proposals must be
submitted to the General Committee (see Division III), which will refer them for
examination to the committees for the various taxonomic groups (see also Art.
15 and Rec. 15A).

Article 70

70.1.  [Article 70, dealing with discordant elements, was deleted by the Leningrad
Congress, 1975.]

Article 71

71.1.  [Article 71, dealing with monstrosities, was deleted by the Leningrad Congress,
1975.]

Article 72

72.1.  A name rejected under Arts. 6367 or 69 is replaced by the name that has
priority (Art.
11) in the rank concerned. If none exists in any rank a new name

must be chosen: (a) the taxon may be treated as new and another name
published for it, or (b) if the illegitimate name is a later homonym, an avowed

substitute (nomen novum) based on the same type as the rejected name may be
published for it. If a name is available in another rank, one of the above
alternatives may be chosen, or (c) a new combination, based on the name in the
other rank, may be published.

72.2.  Similar action is to be taken if transfer of an epithet of a legitimate name
would result in a combination that cannot be validly published
under Arts. 21.3
or 23.4.

Ex. 1.  Linum radiola L. (1753) when transferred to the genus Radiola may not be named Radiola
radiola
(L.) H. Karsten (1882), as that combination is invalid (see Arts. 23.4 and 32.1(b)). The next
oldest name, L. multiflorum Lam. (1779), is illegitimate, being a superfluous name for L. radiola L.
Under Radiola, the species has been given the legitimate name R. linoides Roth (1788).

Note 1.  When a new epithet is required, an author may adopt an epithet previously given to the taxon
in an illegitimate name if there is no obstacle to its employment in the new position or sense; the
resultant combination is treated as the name of a new taxon or as a nomen novum, as the case may be.

Ex. 2.  The name Talinum polyandrum Hooker (1855) is illegitimate, being a later homonym of T.
polyandrum
Ruiz & Pavón (1798). When Bentham, in 1863, transferred T. polyandrum Hooker to
Calandrinia, he called it Calandrinia polyandra. This name is treated as having priority from 1863,
and should be cited as Calandrinia polyandra Bentham, not C. polyandra (Hooker) Bentham.

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Rejection 72

Ex. 3.  Cenomyce ecmocyna Achar. (1810) is a superfluous name for Lichen gracilis L. (1753), and so
is Scyphophora ecmocyna Gray (1821), the type of L. gracilis still being included. However, when
proposing the combination Cladonia ecmocyna, Leighton (1866) explicitly excluded that type and
thereby published a new, legitimate name, Cladonia ecmocyna Leighton.

Recommendation 72A

72A.1.  Authors should avoid adoption of the epithet of an illegitimate name previously published
for the same taxon.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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73 Orthography

 
 
 
 
 

C H A P T E R  V I .   O R T H O G R A P H Y  O F  N A M E S  A N D  E P I T H E T S

A N D  G E N D E R  O F  G E N E R I C N A M E S 

S E C T I O N  1. O R T H O G R A P H Y  O F  N A M E S  A N D  E P I T H E T S

Article 73

73.1.  The original spelling of a name or epithet is to be retained, except for the
correction of typographic or orthographic errors (but see Art. 32.5).

Ex. 1.  Retention of original spelling: The generic names Mesembryanthemum L. (1753) and Amaran-
thus
L. (1753) were deliberately so spelled by Linnaeus and the spelling is not to be altered to
Mesembrianthemum and Amarantus respectively, although these latter forms are philologically
preferable (see Bull. Misc. Inform. 1928: 113, 287). Phoradendron Nutt. is not to be altered to
Phoradendrum. Triaspis mozambica Adr. Juss. is not to be altered to T. mossambica, as in Engler
(Pflanzenw. Ost-Afrikas C: 232. 1895). Alyxia ceylanica Wight is not to be altered to A. zeylanica, as
in Trimen (Handb. Fl. Ceyl. 3: 127. 1895). Fagus sylvatica L. is not to be altered to F. silvatica. The
classical spelling silvatica is recommended for adoption in the case of a new name (Rec. 73E), but the
mediaeval spelling sylvatica is not treated as an orthographic error. Scirpus cespitosus L. is not to be
altered to S. caespitosus.

Ex. 2.  Typographic errors: Globba brachycarpa Baker (1890) and Hetaeria alba Ridley (1896) are
typographic errors for Globba trachycarpa Baker and Hetaeria alta Ridley respectively (see J. Bot. 59:
349. 1921). – Thevetia nereifolia Adr. Juss. ex Steudel is an obvious typographic error for T. neriifolia.

Ex. 3.  Orthographic error: Gluta benghas L. (1771), being an orthographic error for G. renghas,
should be cited as G. renghas L., as has been done by Engler (in A. DC. & C. DC., Monogr. Phan. 4:
225. 1883); the vernacular name used as a specific epithet by Linnaeus is ‘Renghas’, not ‘Benghas’.

Note 1.  Art. 14.10 provides for the conservation of an altered spelling of a generic name.

Ex. 4.  Bougainvillea (see Appendix III, Spermatophyta, no. 2350).

73.2.  The words ‘original spelling’ in this Article mean the spelling employed
when the name was validly published. They do not refer to the use of an initial
capital or small letter, this being a matter of typography (see Art. 21.2, Rec. 73F).

73.3.  The liberty of correcting a name is to be used with reserve, especially if the
change affects the first syllable and, above all, the first letter of the name.

Ex. 5.  The spelling of the generic name Lespedeza is not to be altered, although it commemorates
Vicente Manuel de Céspedes (see Rhodora 36: 130-132, 390-392. 1934).

 
 

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Orthography 73

73.4.  The letters w and y, foreign to classical Latin, and k, rare in that language,
are permissible in Latin plant names.

73.5.  When a name or epithet has been published in a work where the letters u, v
or i, j are used interchangeably or in any other way incompatible with modern
practices (one of those letters is not used or only in capitals), those letters should
be transcribed in conformity with modern botanical usage.

Ex. 6.  Uffenbachia Fabr., not Vffenbachia; Taraxacum Zinn, not Taraxacvm; Curculigo Gaertner,
not Cvrcvligo.

Ex. 7.  Geastrvm hygrometricvm Pers. and Vredo pvstvlata Pers. (1801) should be written respectively
Geastrum hygrometricum and Uredo pustulata.

Ex. 8.  Bromus iaponicus Thunb. (1784) should be written Bromus japonicus.

73.6.  Diacritical signs are not used in Latin plant names. In names (either new or
old) drawn from words in which such signs appear, the signs are to be suppressed
with the necessary transcription of the letters so modified; for example ä, ö, ü
become respectively ae, oe, ue; é, è, ê become e, or sometimes ae; ñ becomes n; ø
becomes oe; å becomes ao; the diaeresis, however, is permissible.

Note 2.  The diaeresis should be used where required in works in which diphthongs are not represen-
ted by special type, e.g. Cephaëlis, not Cephaelis, in works in which there is Arisaema, not Arisæma.

73.7.  When changes made in orthography by earlier authors who adopt person-
al, geographic, or vernacular names in nomenclature are intentional latiniza-
tions, they are to be preserved, except for terminations covered by Art. 73.10.

Ex. 9.  Valantia L. (1753), Gleditsia L. (1753), and Clutia L. (1753), commemorating Vaillant,
Gleditsch, and Cluyt respectively, are not to be altered to Vaillantia, Gleditschia, and Cluytia;
Linnaeus latinized the names of these botanists deliberately as ‘Valantius’, ‘Gleditsius’, and ‘Clutius’.

Ex. 10.  Zygophyllum billardierii DC. was named for J. J. H. de Labillardière (de la Billardière). The
intended latinization is ‘Billardierius’ (in nominative), but the change in the termination is not
acceptable under Art. 73.10 and the name is correctly spelled Z. billardierei DC.

73.8.  The use of an incorrect compounding form in an epithet is treated as an
orthographic error to be corrected (see Rec. 73G).

Ex. 11.  Pereskia opuntiaeflora DC. is to be cited as P. opuntiiflora DC.

Ex. 12.  Cacalia napeaefolia DC. and Senecio napeaefolius (DC.) Schultz-Bip. are to be cited as
Cacalia napaeifolia DC and Senecio napaeifolius (DC.) Schultz-Bip. respectively; the specific epithet
refers to the resemblance of the leaves to those of the genus Napaea (not Napea), and the substitute
(connecting) vowel -i should have been used instead of the genitive singular inflection -ae.

73.9.  The use of a hyphen after a compounding form in an epithet is treated as an
orthographic error to be corrected.

Ex. 13.  Acer pseudoplatanus L., not A. pseudo-platanus; Ficus neoëbudarum Summerh., not F.
neo-ebudarum; Lycoperdon atropurpureum
Vitt., not L. atro-purpureum; Croton ciliatoglandulifer

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73 Orthography

Ortega, not C. ciliato-glandulifer; Scirpus sect. Pseudoëriophorum Jurtzer, not S. sect. Pseudo-
eriophorum
.

Note 3.  Art. 73.9 refers only to epithets (in combinations), not to names of genera or taxa in higher
ranks; a generic name published with a hyphen can be changed only by conservation.

Ex. 14.  Pseudo-salvinia Piton (1940).

Note 4.  A hyphen is permitted in an epithet after a word which could stand independently (not a
compounding form) (see Art. 23.1).

Ex. 15.  Aster novae-angliae L., Coix lacryma-jobi L., Peperomia san-felipensis J. D. Smith, Arctosta-
phylos uva-ursi
(L.) Sprengel, Veronica anagallis-aquatica L. (Art. 23.3).

73.10.  The wrong use of the terminations, for example -i, -ii, -ae, -iae, -anus, and
-ianus, mentioned in Rec. 73C.1 is treated as an orthographic error to be
corrected (see also Art. 32.5).

Ex. 16.  Rosa pissarti Carrière (Rev. Hort. 1880: 314) is a typographic error for R. pissardi (see Rev.
Hort. 1881: 190), which in its turn is treated as an orthographic error for R. pissardii (see Rec.
73C.l(b)).

Recommendation 73A

73A.1.  When a new name or epithet is to be derived from Greek, the transliteration to Latin should
conform to classical usage.

73A.2.  The spiritus asper should be transcribed in Latin as the letter h.

Recommendation 73B

73B.1.  When a new name for a genus, subgenus, or section is taken from the name of a person, it
should be formed as follows:

(a)  When the name of the person ends in a vowel, the letter -a is added (thus Ottoa after Otto; Sloanea
      after Sloane), except when the name ends in -a, when -ea is added (e.g. Collaea after Colla), or in
      -ea (as Correa), when no letter is added.

(b)  When the name of the person ends in a consonant, the letters -ia are added, except when the name
      ends in -er, when -a is added (e.g. Kernera after Kerner). In latinized names ending in -us, this
      termination is dropped before adding the suffix (Dillenia after Dillenius).

(c)  The syllables not modified by these endings retain their original spelling, unless they contain
      letters foreign to Latin plant names or diacritical signs (see Art. 73.6).

Note 1.  Names may be accompanied by a prefix or a suffix, or be modified by anagram or
abbreviation. In these cases they count as different words from the original name.

Ex. 1.  Durvillaea and Urvillea; Lapeirousia and Peyrousea; Englera, Englerastrum, and Englerella;
Bouchea and Ubochea; Gerardia and Graderia; Martia and Martiusia.

Recommendation 73C

73C.1.  Modern personal names may be given Latin terminations and used to form specific and
infraspecific epithets as follows:

(a)  If the personal name ends in a vowel or -er, substantive epithets are formed by adding the genitive
      inflection appropriate to the gender and number of the person(s) honoured (e.g., scopoli-i for
      Scopoli (m), fedschenko-i for Fedtschenko (m), glaziou-i for Glaziou (m), lace-ae for Lace (f),
      hooker-orum for the Hookers), except when the name ends in -a, in which case adding -e (singular)
      or -rum (plural) is appropriate (e.g. triana-e for Triana (m)).

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Orthography 73

(b)  If the personal name ends in a consonant (except -er), substantive epithets are formed by adding
      -i- (stem augmentation) plus the genitive inflection appropriate to the gender and number of the
      person(s) honoured (e.g. lecard-ii for Lecard (m), wilson-iae for Wilson (f), verlot-iorum for the
      Verlot brothers, braun-iarum for the Braun sisters).

(c)  If the personal name ends in a vowel, adjectival epithets are formed by adding -an- plus the
      nominative singular inflection appropriate to the gender of the generic name (e.g., Cyperus heyne-
      anus for Heyne, Vanda lindley-ana for Lindley, Aspidium bertero-anum for Bertero), except when
      the personal name ends in -a in which case -n- plus the appropriate inflection is added (e.g.
      balansa-nus (m), balansa-na (f), and balansa-num (n) for Balansa).

(d)  If the personal name ends in a consonant, adjectival epithets are formed by adding -i- (stem
      augmentation) plus -an- (stem of adjectival suffix) plus the nominative singular inflection
      appropriate to the gender of the generic name (e.g. Rosa webb-iana for Webb, Desmodium griffith-
      ianum for Griffith, Verbena hassler-iana for Hassler).

Note 1.  The hyphens in the above examples are used only to set off the total appropriate termination.

73C.2.  Personal names already in Greek or Latin, or possessing a well-established latinized form,
should be given their appropriate Latin genitive to form substantive epithets (e.g. alexandri from
Alexander or Alexandre, augusti from Augustus or August or Auguste, linnaei from Linnaeus, martii
from Martius, beatricis from Beatrix or Béatrice, hectoris from Hector). (However, modern personal
names are subject to the provisions of Art. 73.10.)
Treating modern names as if they were in Third
Declension should be avoided (e.g. munronis from Munro, richardsonis from Richardson).

73C.3.  In forming new epithets based on personal names the original spelling of the personal name
should not be modified unless it contains letters foreign to Latin plant names or diacritical signs (see
Art. 73.6).

73C.4.  Prefixes and particles ought to be treated as follows:

(a)  The Scottish patronymic prefix ‘Mac’, ‘Mc’ or ‘M’, meaning ‘son of’, should be spelled ‘mac’ and
      united with the rest of the name, e.g. macfadyenii after Macfadyen, macgillivrayi after MacGilli-
      vray, macnabii after McNab, mackenii after M’Ken.

(b)  The Irish patronymic prefix ‘O’ should be united with the rest of the name or omitted, e.g.
      obrienii, brienianus after O’Brien, okellyi after O’Kelly.

(c)  A prefix consisting of an article, e.g. le, la, l’, les, el, il, lo, or containing an article e.g. du, de la, des,
      del, della, should be united to the name, e.g. leclercii after Le Clerc, dubuyssonii after DuBuysson,
      lafarinae after La Farina, logatoi after Lo Gato.

(d)  A prefix to a surname indicating ennoblement or canonization should be omitted, e.g. candollei
      after de Candolle, jussieui after de Jussieu, hilairei after Saint-Hilaire, remyi after St. Rémy; in
      geographical epithets, however, ‘St.’ is rendered as sanctus (m) or sancta (f), e.g. sancti-johannis,
      of St. John, sanctae-helenae, of St. Helena.

(e)  A German or Dutch prefix when it is normally treated as part of the family name, as often
      happens outside its country of origin, e.g. in the United States, may be included in the epithet, e.g.
      vonhausenii after Vonhausen, vanderhoekii after Vanderhoek, vanbruntiae after Mrs. Van Brunt,
      but should otherwise be omitted, e.g. iheringii after von Ihering, martii after von Martius, steenisii
      after van Steenis, strassenii after zu Strassen, vechtii after van der Vecht.

Recommendation 73D

73D.1.  An epithet derived from a geographical name is preferably an adjective and usually takes the
termination -ensis, -(a)nus, -inus, or -icus.

Ex. 1.  Rubus quebecensis (from Quebec), Ostrya virginiana (from Virginia), Eryngium amorginum
(from Amorgos),
Polygonum pensylvanicum (from Pennsylvania).
 
 

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73 Orthography

Recommendation 73E

73E.1.  A new epithet should be written in conformity with the original spelling of the word or words
from which it is derived and in accordance with the accepted usage of Latin and latinization (see Art.
23.5).

Ex. 1.  sinensis (not chinensis).

Recommendation 73F

73F.1.  All specific and infraspecific epithets should be written with a small initial letter, although
authors desiring to use capital initial letters may do so when the epithets are directly derived from the
names of persons (whether actual or mythical), or are vernacular (or non-Latin) names, or are former
generic names.

Recommendation 73G

73G.1.  A compound name or an epithet which combines elements derived from two or more Greek
or Latin words should be formed, as far as practicable, in accordance with classical usage (see Art.
73.8). This may be stated as follows:

(a)  In a true compound, a noun or adjective in non-final position appears as a stem without case
       ending with one of the following modifications to derive its compounding forms:

       (1) If the stem ends in a consonant, a connecting vowel (-o- in Greek, -i- in Latin) is inserted
       before a following consonant (Leont-o-podium, stem leont-; cord-i-folius, stem cord-). Before a
       following vowel the connecting vowel is omitted (Leont-ice; cord-atus).

       (2) If the stem ends, or appears to end, in the vowels -a, oe, -o, or -u, this stem vowel is normally
       deleted before a following consonant. For Greek words, -o is substituted (Acantho-panax, stem
       acantha-; Limno-charis, stem limne-; Cyclo-sorus, stem cyclo-). For Latin words, -i is substituted
       (magnolii-florus, stem magnolia-; lilii-florus, stem lilio-; querci-folius, stem quercu-), except for the
       rare e-stems. Before a following vowel the above stem vowels are deleted and the Greek -o and
       Latin -i are not substituted (Acanth-ella, Limn-anthes, Cycl-anthus, Magnoli-aceae, Lili-ales,
       querc-etum). In certain words the stem vowel may be preserved; this can only be determined by
       comparison with existing classical compounds (Coryne-phorus, stem coryne-; re-cula, re-al, stem
       re-).

       (3) If the stem ends in the vowels -y, -i, or the rare diphthongs -au, -eu, or -ou, the stem vowel is
       normally preserved (Pachy-phytum, Pachy-anthus, stem pachy-; Lysi-machia, Lisi-anthus, stem
       lysi-; Nau-clea, stem nau-). For certain stems, such as those of Greek nouns ending in -y or
       sometimes -i. the connecting vowel -o- is added before a consonant (Ichthy-o-there, stem ichthy-;
       Ophi-o-glossum, stem ophi-). The Greek diphthong stem endings are normally preserved but
       often undergo changes (Bo-opis, stem bou-; oreo-comus, stem oreu-; Basilo-xylon, stem basileu-).

(b)  A pseudocompound is a noun or adjectival phrase treated as if it were a single compound word.
       In a pseudocompound, a noun or adjective in a non-final position appears as a word with a case
       ending, not as a modified stem. Examples are: nidus-avis (nest of bird), Myos-otis (ear of mouse),
       cannae-folius (leaf of canna), albo-marginatus (margined with white), etc. Some irregular forms
       have been developed on the analogy of pseudocompounds, such as atro-purpureus (purple with
       black, where the correct phrasing could have been purpureus cum atro). Others have been
       deliberately introduced to reveal etymological differences when different word elements have the
       same compounding forms, such as tubi- from tube (tubus, tubi, stem tubo-) or from trumpet (tuba,
       tuba, stem tuba-) where tubaeflorus can only mean trumpet-flowered; also carici- is the com-
       pounding form from both papaya (carica, caricae, stem carica-) and sedge (carex, caricis, stem
       caric-) where caricaefolius can only mean papaya-leaved. The latter use of genitive singular of
       First Declension for pseudocompounding is treated as an error to be corrected unless it makes an
       etymological distinction.

(c)  Some common irregular forms are used in compounding. Examples are hydro- and hydr- (Hydro-
       phyllum) where the regular noun stem is hydat-; calli- (Calli-stemon) where the regular adjective
       stem is calo-; and meli- (Meli-osma, Meli-lotus) where the regular noun stem is melit-.
 

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Gender 74–75

Note 1.  The hyphens in the above examples are given solely for explanatory reasons. For the use of
hyphens in botanical names and epithets see Arts. 20.3, 23.1, and 73.9.

Recommendation 73H

73H.1.  Epithets of fungus names derived from the generic name of the host plant should be spelled in
accordance with the accepted spelling of this name; other spellings are regarded as orthographic
variants to be corrected (see Art. 75).

Ex. 1.  Phyllachora anonicola Chardon is to be altered to P. annonicola, since the spelling Annona is
now accepted in preference to Anona.Meliola albizziae Hansford & Deighton is to be altered to M.
albiziae
, since the spelling Albizia is now accepted in preference to Albizzia.

Recommendation 73I

73I.1.  The etymology of new names and epithets should be given when the meaning of these is not
obvious.

Article 74

[Article 74, dealing with variant spellings of Linnaean generic names, was deleted
by the Sydney Congress, 1981 (but see Art. 13.4).]

Article 75

75.1.  Only one orthographic variant of any one name is treated as validly
published, the form which appears in the original publication except as provided
in Art. 73 (orthographic and typographic errors), Art. 14.10 (conserved spel-
lings), and Art. 32.5 (incorrect Latin terminations).

Note 1.  Orthographic variants are the various spelling, compounding, and inflectional forms of a
name or epithet (including typographic errors), only one type being involved. (For confusingly
similar names based on different types, see Art. 64.2-3.)

75.2.  If orthographic variants of a name appear in the original publication, the
one that conforms to the rules and best suits the recommendations of Art. 73 is to
be retained; otherwise the first author who explicitly adopts one of the variants,
rejecting the other(s), must be followed.

75.3.  The orthographic variants of a name are to be automatically corrected to
the validly published form of that name. Whenever such a variant appears in
print, it is to be treated as if it were printed in its corrected form.

S E C T I O N  2 .  G E N D E R  O F  G E N E R I C  N A M E S

Recommendation 75A

75A.1.  A Greek or Latin word adopted as a generic name should retain its gender. When the gender
varies the author should choose one of the alternative genders. In doubtful cases general usage should
be followed. The following names, however, should be treated as feminine in accordance with
 

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75 Gender

botanical custom, irrespective of classical usage or the author’s original usage: Adonis, Diospyros,
Hemerocallis, Orchis, Stachys, and Strychnos.

Ex. 1.  The classical gender of Atriplex varied (e.g. feminine in Columella, neuter in Pliny); Linnaeus
treated the name as feminine and should be followed. However, Phyteuma was consistently neuter
(e.g. Dioscorides, Pliny), Sicyos consistently masculine (Theophrastus, Dioscorides), and Erigeron
consistently masculine (Theophrastus, Dioscorides, Pliny), and these should retain their classical
gender even though Linnaeus treated them otherwise.
 

75A.2.  Generic names compounded from two or more Greek or Latin words should take the gender
of the last. If the termination is altered, however, the gender should follow it.

(a) Modern compounds ending in -codon, -myces, -odon, -panax, -pogon, -stemon, and other mascu-
      line words should be masculine, irrespective of the fact that the generic names Andropogon L. and
      Oplopanax (Torrey & A. Gray) Miq. were originally treated as neuter by their authors.

(b)   Similarly, all modern compounds ending in -achne, -chlamys, -daphne, -mecon, -osma (the
      modern transcription of the feminine Greek word osmé) and other feminine words should be
      feminine, irrespective of the fact that Dendromecon Bentham and Hesperomecon E. Greene were
      originally ascribed the neuter gender. An exception should be made in the case of names ending in
      -gaster, which strictly speaking ought to be feminine, but which should be treated as masculine in
      accordance with botanical custom.

(c) Similarly, all modern compounds ending in -ceras, -dendron, -nema, -stigma, -stoma and other
      neuter words should be neuter, irrespective of the fact that Robert Brown and Bunge respectively
      made Aceras and Xanthoceras feminine. An exception should be made for names ending in
      -anthos (or -anthus) and -chilos (-chilus or -cheilos), which ought to be neuter, since that is
      the gender of the Greek words anthos and cheilos, but which have generally been treated as
      masculine and should have that gender assigned to them.

Ex. 2.  Compound generic names where the termination of the last word is altered: Stenocarpus,
Dipterocarpus, and all other modern compounds ending in the Greek masculine -carpos (or -carpus),
e.g. Hymenocarpos, should be masculine; those in -carpa or -carpaea, however, should be feminine
e.g. Callicarpa and Polycarpaea; and those in -carpon, -carpum, or -carpium should be neuter, e.g.
Polycarpon, Ormocarpum, and Pisocarpium.

75A.3.  Arbitrarily formed generic names or vernacular names or adjectives used as generic names,
whose gender is not apparent, should take the gender assigned to them by their authors. Where the
original author has failed to indicate the gender, the next subsequent author may choose a gender,
and his choice should be accepted.

Ex. 3.  Taonabo Aublet should be feminine: Aublet’s two species were T. dentata and T. punctata.

Ex. 4.  Agati Adanson was published without indication of gender: the feminine gender was assigned
to it by Desvaux (J. Bot. Agric. 1: 120. 1813), who was the first subsequent author to adopt the name,
and his choice should be accepted.

Ex. 5.  Boehmer (in Ludwig, Def. Gen. Pl. ed. 3. 436. 1760) and Adanson (Fam. Pl. 2: 356. 1763)
failed to indicate the gender of Manihot: the first author to supply specific epithets was Crantz (Inst.
Rei Herb. 1: 167. 1766), who proposed the names Manihot gossypiifolia, etc., and Manihot should
therefore be treated as feminine.

75A.4.  Generic names ending in -oides or -odes should be treated as feminine and those ending in
-ites as masculine, irrespective of the gender assigned to them by the original author.
 
 
 
 

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Gender 75

Recommendation 75B

75B.1.  When a genus is divided into two or more genera, the gender of the new generic name or
names should be that of the generic name that is retained.

Ex. 1.  When Boletus is divided, the gender of the new generic names should be masculine: Xeroco-
mus
, Boletellus, etc.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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Div.III.1–Div.III.3 Modification of Code

 
 
 
 
 
 

D I V I S I O N  I I I .  P R O V I S I O N S  F O R  M O D I F I C A T I O N 

O F  T H E  C O D E
 

Div.III.1.  Modification of the Code. The Code may be modified only by action
of a plenary session of an International Botanical Congress on a resolution
moved by the Nomenclature Section of that Congress.*
 

Div.III.2.  Nomenclature Committees. Permanent Nomenclature Committees
are established under the auspices of the International Association for Plant
Taxonomy. Members of these committees are elected by an International Botan-
ical Congress. The Committees have power to co-opt and to establish subcom-
mittees; such officers as may be desired are elected.
(1)  General Committee, composed of the secretaries of the other committees,
      the rapporteur-général, the president and the secretary of the International
      Association for Plant Taxonomy, and at least 5 members to be appointed by
      the Nomenclature Section. The rapporteur-général is charged with the
      presentation of nomenclature proposals to the International Botanical Con-
      gress.
(2)  Committee for Spermatophyta.
(3)  Committee for Pteridophyta.
(4)  Committee for Bryophyta.
(5)  Committee for Fungi and Lichens.
(6)  Committee for Algae.
(7)  Committee for Hybrids.
(8)  Committee for Fossil Plants.
(9)  Editorial Committee, charged with the preparation and publication of the
      Code in conformity with the decisions adopted by the International Botani-
      cal Congress. Chairman: the rapporteur-général of the previous Congress,
      who is charged with the general duties in connection with the editing of the
      Code.
 

Div.III.3.  The Bureau of Nomenclature of the International Botanical Con-
gress.
Its officers are: (1) the president of the Nomenclature Section, elected by

*  In the event that there should not be another International Botanical Congress, authority for the
International Code of Botanical Nomenclature shall be transferred to the International Union of
Biological Sciences or to an organization at that time corresponding to it. The General Committee is
empowered to define the machinery to achieve this.

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Modification of Code Div.III.4

the organizing committee of the International Botanical Congress in question;
(2) the recorder, appointed by the same organizing committee; (3) the
rapporteur-général, elected by the previous Congress; (4) the vice-rapporteur,
elected by the organizing committee on the proposal of the rapporteur-général.
 

Div.III.4.  The voting on nomenclature proposals is of two kinds: (a) a prelimi-
ary guiding mail vote and (b) a final and binding vote at the Nomenclature
Section of the International Botanical Congress.
 
Qualifications for voting:

(a)  Preliminary mail vote:
      (1) The members of the International Association for Plant Taxonomy.
      (2) The authors of proposals.
      (3) The members of the nomenclature committees.

Note 1.  No accumulation or transfer of personal votes is permissible.

(b)  Final vote at the sessions of the Nomenclature Section:
      (1) All officially enrolled members of the Section. No accumulation or
      transfer of personal votes is permissible.
      (2) Official delegates or vice-delegates of the institutes appearing on a list
      drawn up by the Bureau of Nomenclature of the International Botanical
      Congress and submitted to the General Committee for final approval; such
      institutes are entitled to 1-7 votes, as specified on the list.* Transfer of
      institutional votes to specified vice-delegates is permissible, but no single
      person will be allowed more than 15 votes, his personal vote included.
      Institutional votes may be deposited at the Bureau of Nomenclature to be
      counted in a specified way for specified proposals.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

*  The Sydney Congress directed that no single institution, even in the wide sense of the term, shall be
entitled to more than 7 votes.

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H.1–H.3 Hybrids

 
 
 
 
 
 

A P P E N D I X  I

N A M E S  O F  H Y B R I D S

Article H.1

H.1.1.  Hybridity is indicated by the use of the multiplication sign  × , or by the
addition of the prefix ‘notho-’* to the term denoting the rank of the taxon.

Article H.2

H.2.1.  A hybrid between named taxa may be indicated by placing the multipli-
cation sign between the names of the taxa; the whole expression is then called a
hybrid formula.

Ex. 1.  Agrostis L.  ×  Polypogon Desf.; Agrostis stolonifera L.  ×  Polypogon monspeliensis (L.) Desf.;

Salix aurita L.  ×  S. caprea L.; Mentha aquatica L.  ×  M. arvensis L.  ×  M. spicata L.; Polypodium
vulgare
subsp. prionodes Rothm.  ×  subsp. vulgare
.

Recommendation H.2A

H.2A.1.  It is usually preferable to place the names or epithets in a formula in alphabetical order. The
direction of a cross may be indicated by including the sexual symbols (♀: female; ♂: male) in the
formula, or by placing the female parent first. If a non-alphabetical sequence is used, its basis should
be
clearly indicated.

Article H.3

H.3.1.  Hybrids between representatives of two or more taxa may receive a
name.
The hybrid nature of a taxon is indicated by placing the multiplication
sign
× before the name of an intergeneric hybrid or before the epithet of an
interspecific hybrid, or by prefixing the term ‘notho-’ (optionally abbreviated
‘n-’) to the term denoting the rank of the taxon (see Art. 4.1). All such taxa are
designated nothotaxa.

Ex. 1.  (The putative or known parentage is found in Art. H.2, Ex. l.)  × Agropogon P. Fourn.;
 × Agropogon littoralis (Smith) C. E. Hubb.; Salix  × capreola Kerner ex Andersson; Mentha  × smi-
thiana
R. A. Graham; Polypodium vulgare nothosubsp. mantoniae (Rothm.) Schidlay.
 

*  From the Greek nothos (νοθος) meaning hybrid.

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Hybrids H.4

H.3.2.  A nothotaxon cannot be designated unless at least one parental taxon is
known or can be postulated.

H.3.3.  The epithet of a nothospecies is termed a collective epithet.

H.3.4.  For purposes of homonymy and synonymy the multiplication sign and
the prefix ‘notho-’ are disregarded.

Ex. 2.   × Hordelymus Bacht. & Darevskaja (1950) (= Elymus L.  ×  Hordeum L.) is a later homonym
of Hordelymus (Jessen) Jessen (1885).

Note 1.  Taxa which are believed to be of hybrid origin need not be designated as nothotaxa.

Ex. 3.  The true-breeding tetraploid raised from the artificial cross Digitalis grandiflora L.  ×  D.
purpurea
L. may, if desired, be referred to as D. mertonensis Buxton & Darl.; Triticum aestivum L. is
treated as a species although it is not found in nature and its genome has been shown to be composed
of those of T. monococcum, Aegilops speltoides, and A. squarrosa;  the taxon known as Phlox
divaricata subsp. laphamii (Wood) Wherry is believed by Levin (Evolution 21: 92-108. 1967) to be a
stabilized product of hybridization between P. divaricata L. subsp. divaricata and P. pilosa subsp.
ozarkana Wherry.

Note 2.  The term ‘collective epithet is used in the International Code of Nomenclature for Cultivat-
ed Plants-1980 to include also epithets in modern language.

Recommendation H.3A

H.3A.1.  The multiplication sign in the name of a nothotaxon should be placed against the initial
letter of the name or epithet. However, if the mathematical symbol is not available and the letter x is
used instead, a single letter space may be left between it and the epithet if this helps to avoid
ambiguity. The letter x should be in lower case.

Article H.4

H.4.1.  When all the parent taxa can be postulated or are known, a nothotaxon is
circumscribed so as to include all individuals (as far as they can be recognized)
derived from the crossing of the stated set of parent taxa (i.e. not only the but
subsequent filial generations and also back-crosses and combinations of these).
There can thus be only one correct name corresponding to a particular hybrid
formula; this is the earliest legitimate name (see Art. 6.3) in the appropriate rank
(Art. H.5), and other names to which the same hybrid formula applies are
synonyms of it.

Ex. 1.  The names Oenothera  × wienii Renner ex Rostański (1977) and O.  × hoelscheri Renner ex
Rostański (1968) are both considered to apply to the hybrid O. rubricaulis  ×  O. depressa; the types of
the two nothospecific names are known to differ by a whole gene-complex; nevertheless, the later
name is treated as a synonym of the earlier.

Note 1.  Variation within nothospecies and nothotaxa of lower rank may be treated according to Art.
H.12 or, if appropriate, according to the International Code of Nomenclature for Cultivated Plants-
1980.

 
 
 

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H.5–H.6 Hybrids

Article H.5

H.5.1.  A nothotaxon has the same rank as its postulated or known parent taxa.

H.5.2.  If the postulated or known parent taxa are of unequal rank the nothotax-
on must have the lower rank (see Art. H.11.2).

Article H.6

H.6.1.  A nothogeneric name (i.e. the name at generic rank for a hybrid between
two or more genera)
is a condensed formula or is equivalent to a condensed
formula.

H.6.2.  The nothogeneric name of a bigeneric hybrid is a condensed formula in
which the names adopted for the parental genera are combined into a single
word, using the first part or the whole of one, the last part or the whole of the
other (but not the whole of both) and, if desirable, a connecting vowel.

Ex. 1.   × Agropogon P. Fourn. (= Agrostis  ×  Polypogon);  × Gymnanacamptis Asch. & Graebner
(= Anacamptis  ×  Gymnadenia);   × Cupressocyparis Dallimore (= Chamaecyparis  ×  Cupressus);
 × Seleniphyllum Rowley (= Epiphyllum × Selenicereus).

Ex. 2.   × Amarcrinum Coutts (1925) is correct for Amaryllis L.  ×  Crinum L., not  × Crindonna
Ragion. (1921). The latter name was proposed for the same nothogenus, but was formed from the
generic name adopted for one parent (Crinum) and a synonym (Belladonna Sweet) of the generic
name adopted for the other (Amaryllis). Being contrary to Art. H.6, it is not validly published under
Art. 32.1(b).

Ex. 3.  The name  × Leucadenia Schlechter is correct for Leucorchis E. Meyer  ×  Gymnadenia R. Br.,
but if the generic name Pseudorchis Séguier is adopted instead of Leucorchis,   × Pseudadenia P. Hunt
is correct.

Ex. 4.   × Aporophyllum Johnson when first published was defined as Aporocactus  ×  members of the
‘Orchid Cacti’. The latter constitute the epicacti (‘epiphyllums’ of horticulture)—a complex descend-
ed from 4 or 5 separate genera. This name is hence not validly published (Art. 32.1(b)) because it
conflicts with Art. H.6.3. For the bigeneric hybrid Aporocactus  ×  Epiphyllum a different name
applies ( × Aporepiphyllum Rowley).

Ex. 5.  Boivin (1967) published  × Maltea for what he considered to be the intergeneric hybrid
Phippsia  ×  Puccinellia. As this is not a condensed formula, the name cannot be used for that
intergeneric hybrid, for which the correct name is  × Pucciphippsia Tzvelev (1971). Boivin did,
however, provide a Latin description and designate a type; consequently, Maltea is a validly
published generic name and is correct if its type is treated as belonging to a separate genus, not to a
nothogenus.

H.6.3.  The nothogeneric name of an intergeneric hybrid derived from four or
more genera is formed from the name of a collector, grower, or student of the
group, to which is added the termination -ara; no such name may exceed eight
syllables. Such a name is regarded as a condensed formula.

Ex. 6.   × Potinara hort. (= Brassavola  ×  Cattleya  ×  Laelia  ×  Sophronitis).
 
 

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Hybrids H.7–H.8

H.6.4.  The nothogeneric name of a trigeneric hybrid is either (a) a condensed
formula in which the three names adopted for the parental genera are combined
into a single word not exceeding eight syllables, using the whole or first part of
one, followed by the whole or any part of another, followed by the whole or last
part of the third (but not the whole of all three) and, if desirable, one or two
connecting vowels, or (b) a name formed like that of a nothogenus derived from
four or more genera, i.e., from a personal name to which is added the termination
-ara.

Ex. 7.   × Sophrolaeliocattleya hort. ( = Cattleya  ×  Laelia  ×  Sophronitis);  × Vascostylis hort. (=
Ascocentrum  ×  Rhynchostylis  ×  Vanda);  × Rodrettiopsis Moir ( = Comparettia  ×  Ionopsis  × 
Rodriguezia);   × Wilsonara hort. ( = Cochlioda  ×  Odontoglossum  ×  Oncidium).

Article H.7

H.7.1.  The name of a nothotaxon which is a hybrid between subdivisions of a
genus is a combination of an epithet, which is a condensed formula formed in the
same way as a nothogeneric name (Art. H.6.2), with the name of the genus.

Ex. 1.   × Ptilostemon nothosect. Platon Greuter (Boissiera 22: 159. 1973), comprising hybrids between
Ptilostemon sect. Platyrhaphium Greuter and P. sect. Ptilostemon; Ptilostemon nothosect. Plinia
Greuter (Boissiera 22: 158. 1973), comprising hybrids between Ptilostemon sect. Platyrhaphium and
P. sect. Cassinia Greuter.

Article H.8

H.8.1.  When the name or epithet of a nothotaxon is a condensed formula (Arts.
H.6 and H.7), the parental names used in its formation must be those which are
correct for the particular circumscription, position, and rank accepted for the
parental taxa.

Ex. 1.  If the genus Triticum L. is interpreted on taxonomic grounds as including Triticum (s. str.) and
Agropyron Gaertner, and the genus Hordeum L. as including Hordeum (s. str.) and Elymus L., then
hybrids between Agropyron and Elymus as well as between Triticum (s. str.) and Hordeum (s. str.) are
placed in the same nothogenus,  × Tritordeum Asch. & Graebner (1902). If, however, Agropyron is
separated generically from Triticum, hybrids between Agropyron and Hordeum (s. str. or s. lat.)
are placed in the nothogenus  × Agrohordeum A. Camus (1927). Similarly, if Elymus is separated
generically from
Hordeum, hybrids between Elymus and Triticum (s. str. or s. lat.) are placed in the
nothogenus  × Elymotriticum P. Fourn. (1935). If both
Agropyron and Elymus are given generic
rank, hybrids between them are placed in the nothogenus
 × Agroelymus A. Camus (1927);  × Tritor-
deum
is then restricted to hybrids between Hordeum (s. str.) and Triticum (s. str.), and hybrids
between Elymus and Hordeum are placed in  × Elyhordeum Mansf. ex Tsitsin & Petrova (1955), a
substitute name for  × Hordelymus Bacht. & Darevskaja (1950) non Hordelymus (Jessen) Jessen
(1885).

H.8.2.  Names ending in -ara for nothogenera, which are equivalent to con-
densed formulae (Art. H.6.3-4), are applicable only to plants which are accepted
taxonomically as derived from the parents named.

Ex. 2.  If Euanthe is recognized as a distinct genus, hybrids simultaneously involving its only species,

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H.9–H.10 Hybrids

E. sanderiana, and the three genera Arachnis, Renanthera, and Vanda must be placed in  × Cogniauxa-
ra
Garay & H. Sweet; if on the other hand E. sanderiana is included in Vanda, the same hybrids are
placed in  × Holttumara hort. (Arachnis  ×  Renanthera  ×  Vanda).

Article H.9

H.9.1.  In order to be validly published, the name of a nothogenus or of a
nothotaxon with the rank of subdivision of a genus (Arts. H.6 and H.7) must be
effectively published (see Art. 29) with a statement of the names of the parent
genera or subdivisions of genera, but no description or diagnosis is necessary,
whether in Latin or in any other language.

Ex. 1.  Validly published names:  × Philageria Masters (1872), published with a statement of parent-
age, Lapageria  ×  Philesia; Eryngium nothosect. Alpestria Burdet & Miège, pro sect. (Candollea 23:
116. 1968), published with a statement of its parentage, Eryngium sect. Alpina  ×  sect. Campestria;
 × Agrohordeum A. Camus (1927) (=Agropyron Gaertner  ×  Hordeum L.), of which  × ‘Hordeopyron’
Simonet (1935, Hordeopyrum) is a later synonym.

Note 1.  Since the names of nothogenera and nothotaxa with the rank of a subdivision of a genus are
condensed formulae or treated as such, they do not have types.

Ex. 2.  The name  × Ericalluna bealei Krüssm. (1960) was published for plants which were thought to
be variants of the cross Calluna vulgaris  ×  Erica cinerea. If it is considered that these are not hybrids,
but are forms of Erica cinerea, the name  × Ericalluna Krüssm. remains available for use if and when
known or postulated plants of Calluna  ×  Erica should appear.

Ex. 3.   × Arabidobrassica Gleba & Fr. Hoffm. (Naturwissenschaften 66: 548. 1979), a nothogeneric
name which was validly published with a statement of parentage for the result of somatic hybridiza-
tion by protoplast fusion of Arabidopsis thaliana with Brassica campestris, is also available for
intergeneric hybrids resulting from normal crosses between Arabidopsis and Brassica, should any be
produced.

Note 2.  However, names published merely in anticipation of the existence of a hybrid are not validly
published under Art. 34.1(b).

Article H.10

H.10.1.  Names of nothotaxa at the rank of species or below must conform with
the provisions (a) in the body of the Code applicable to the same ranks and (b)
in Art. H.3. Infringements of Art. H.3.1. are to be corrected.

H.10.2.  Taxa previously published as species or infraspecific taxa which are later
considered to be nothotaxa may be indicated as such, without change of rank, in
conformity with Arts. 3 and 4 and by the application of Art. 50 (which also
operates in the reverse direction).

H.10.3.  The following are considered to be formulae and not true epithets:
designations consisting of the epithets of the names of the parents combined in
unaltered form by a hyphen, or with only the termination of one epithet changed,
or consisting of the specific epithet of the name of one parent combined with the
generic name of the other (with or without change of termination).

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Hybrids H.11

Ex. 1.  The designation Potentilla atrosanguinea-pedata published by Maund (Bot. Gard. 5: no. 385,
t. 97. 1833) is considered to be a formula meaning Potentilla atrosanguinea Lodd. ex D. Don  ×  P.
pedata
Nestler.

Ex. 2.  Verbascum nigro-lychnitis Schiede (Pl. Hybr. 40. 1825) is considered to be a formula,
Verbascum lychnitis L.  ×  V. nigrum L.; the correct binary name for this hybrid is Verbascum
× schiedeanum Koch (1844).

Ex. 3.  The following names include true epithets: Acaena  × anserovina Orch. (1969) (from anserini-
folia
and ovina); Micromeria  × benthamineolens Svent. (1969) (from benthamii and pineolens).

Note 1.  Since the name of a nothotaxon at the rank of species or below has a type, statements of
parentage play a secondary part in determining the application of the name.

Ex. 4.  Quercus  × deamii Trel. was described as Q. alba L.  ×  Q. muehlenbergii Engelm. However,
progeny grown from acorns from the type tree led Bartlett to conclude that the parents were in fact Q.
macrocarpa
Michx. and Q. muehlenbergii. If this conclusion is accepted, the name Q.  × deamii applies
to Q. macrocarpa  ×  Q. muehlenbergii, and not to Q. alba  ×  Q. muehlenbergii.

Recommendation H.10A

H.10A.1.  In forming epithets for nothotaxa at the rank of species and below, authors should avoid
combining parts of the epithets of the names of the parents.

Recommendation H.10B

H.10B.1.  For hybrids between named infraspecific taxa the use of hybrid formulae is more informa-
tive, and entails less danger of confusion, than the naming of nothotaxa.

Article H.11

H.11.1.  The name of a nothospecies of which the postulated or known parent
species belong to different genera is a combination of a nothospecific (collective)
epithet with a nothogeneric name.

Ex. 1.   × Heucherella tiarelloides Wehrh. ex Stearn (considered to be Heuchera  × brizoides hort.
× Tiarella cordifolia L., for which Heuchera  × tiarelloides is incorrect).

Ex. 2.  When Orchis fuchsii Druce was renamed Dactylorhiza fuschsii (Druce) Soó the name  × Orchi-
coeloglossum mixtum
Asch. & Graebner (for its hybrid with Coeloglossum viride (L.) Hartman)
became the basis of the necessary new combination  × Dactyloglossum mixtum (Asch. & Graebner)
Rauschert (1969).

H.11.2.  The epithet of an infraspecific nothotaxon, of which the postulated or
known parental taxa are assigned to different taxa at a higher rank, may be
placed subordinate to the name of a nothotaxon at that higher rank (see Art.
24.1). If this higher-ranking nothotaxon is a nothospecies the name of the
subordinate nothotaxon is a combination of its epithet with the nothospecific
name (but see Rec. H.10B).

Ex. 3.  Mentha  ×  piperita L. nothosubsp. piperita (= M. aquatica L.  ×  M. spicata L. subsp. spicata);
Mentha  × piperita nothosubsp. pyramidalis (Ten.) R. Harley ( = M. aquatica L.  ×  M. spicata subsp.
tomentosa (Briq.) R. Harley).
 
 

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H.12 Hybrids

Article H.12

H.12.1.  Subordinate taxa within nothotaxa of specific or infraspecific rank may
be recognized without an obligation to specify parent taxa at the subordinate
rank. In this case non-hybrid infraspecific categories of the appropriate rank are
used.

Ex. 1.  Mentha  × piperita forma hirsuta Sole; Populus  × canadensis var. serotina (Hartig) Rehder and
P.  × canadensis var. marilandica (Poiret) Rehder (see also Art. H.4, Note 2).

Note 1.  As there is no statement of parentage at the rank concerned there is no control of
circumscription at this rank by parentage (compare Art. H.4.).

Note 2.  It is not feasible to treat subdivisions of nothospecies by the methods of both Art. H.10 and
H.12.1 at the same rank.

H.12.2.  Names published at the rank of nothomorph* are treated as having
been published as names of varieties (see Art. 50).
 
 

A P P E N D I X  I I 

 
NOMINA FAMILIARUM CONSERVANDA see pp. 249-269.
 
 

A P P E N D I X  I I I
 

NOMINA GENERICA CONSERVANDA ET REJICIENDA see pp. 270-426.
 
 

A P P E N D I X  I V
 

NOMINA UTIQUE REJICIENDA see p. 427.

 
 
 
 
 
 
 
 
 

*  Previous editions of the Code (1978, Art. H.10, and the corresponding article in earlier editions)
permitted only one rank under provisions equivalent to H.12. That rank was equivalent to variety
and the category was termed ‘nothomorph’.

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Guide types T.1–T.4

 
 
 
 
 
 
 

           G U I D E  F O R  T H E  D E T E R M I N A T I O N  O F  T Y P E S 

 
 

The following is intended as a guide to the determination or selection of the
nomenclatural types of previously published names. Where the application of a
rule is concerned, reference is made to the appropriate Article.

T.1.  The choice made by the original author, if definitely expressed at the time of
the original publication of the name of the taxon, is final. If he included only one
element, that one must always be accepted as the holotype (Arts. 7, 9, 10). If a new
name is based on a previously published description of the taxon, the same
considerations apply to material cited by the earlier author.

T.2.  A new name published as an avowed substitute (nomen novum) for an older
name is typified by the type of the older name (Art. 7.9).

T.3.  A lectotype may be chosen only when an author failed to designate a
holotype, or when, for species or taxa of lower rank, the type has been lost or
destroyed (Art. 7.4).

T.4.  Designation of a lectotype should be undertaken only in the light of an
understanding of the group concerned. In choosing a lectotype, all aspects of the
protologue should be considered as a basic guide.
Mechanical methods, such as
the automatic selection of the first species or specimen cited or of a specimen
collected by the person after whom a species is named, should be avoided as
unscientific and productive of possible future confusion and further change (see
Art. 8.).

(a)  A lectotype must be chosen from among elements that were definitely
       studied by the author up to the time the name of the taxon was published.

(b)  A specimen is to be given preference over pre-Linnaean or other cited
       descriptions or illustrations when lectotypes of names of species or infra-
       specific taxa are designated (see Art. 9.3)

(c)  If a holotype was designated by the original author and has been lost or
       destroyed, an isotype (Art. 7.6), if such exists, must be chosen as the lecto-
       type. If no holotype was designated by the original author and if syntypes
       (Art. 7.7) exist, one of them must be chosen as the lectotype. If no holotype
       was designated by the original author and if no syntypes are extant, the

 
 
 

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T.5–T.6 Guide types

       lectotype should be chosen from among duplicates* of the syntypes (isosyn-
       types), if such exist. If neither an isotype, a syntype, nor an isosyntype is
       extant, a paratype** if such exists, may be chosen as lectotype.

(d)  In choosing a lectotype, any indication of intent by the author of a name
       should be given preference unless such indication is contrary to the proto-
       logue. Such indications are manuscript notes, annotations on herbarium
       sheets, recognizable figures, and epithets such as typicus, genuinus, vulgaris,
       communis, etc.

(e)  In cases where two or more heterogeneous elements were included in or cited
       with the original description, the lectotype should be so selected as to
       preserve current usage. In particular, if another author has already segregat-
       ed one or more elements as other taxa, the residue or part of it should be
       designated as the lectotype provided that this element is not in conflict with
       the original description or diagnosis. If it can be shown that the element thus
       selected is in serious conflict with the protologue, then one of the previously
       segregated elements is to be selected as the lectotype.

(f)  The first choice of a lectotype must be followed by subsequent workers (Art.
       8) unless the holotype is rediscovered, or unless it can be shown that the
       choice was in serious conflict with the protologue, or that it was based on a
       largely mechanical method of selection (see also Art. 9.2).

T.5.  A neotype may be designated only when all of the originally cited material
or material seen by the author but not cited, and its duplicates, are believed lost
or destroyed; a neotype may be selected from any material that is not original

material (Art. 7.8). In selecting a neotype particular care and critical knowledge
are essential, as the reviewer usually has no guide except his own judgment as to
what best fits the protologue. If his selection proves to be faulty it will inevitably

result in further change. The first choice of a neotype must be followed by
subsequent workers unless any of the original material is rediscovered, or unless
the choice neglected an available lectotype, or if it can be shown that the choice was
in serious conflict with the protologue. A lectotype always takes precedence over
a neotype (Art. 7.4).

T.6.  For the name of a fossil species, the lectotype, when one is needed, should, if
possible, be a specimen illustrated at the time of the first valid publication (Art.
7.15).

 
 
 

*  The word duplicate is here given its usual meaning in herbarium curatorial practice. It is part of a
single gathering made by a collector at one time. However, the possibility of a mixed gathering must
always be considered by an author choosing a lectotype and corresponding caution used.

**  A paratype is a specimen cited in the protologue other than the holotype, isotype(s), or syntypes.
In most cases where no holotype was designated there will also be no paratypes, since all the cited
specimens will be syntypes. However, in cases where an author cited two or more specimens as types
(Art. 7.5) the remaining cited specimens are paratypes and not syntypes.

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text: © 1983, IAPT  —  web-edition: © 2014, Paul van Rijckevorsel

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