Montreal Code (1961)

INTERNATIONAL CODE OF BOTANICAL NOMENCLATURE

PREAMBLE

Botany requires a precise and simple system of nomenclature used by botanists
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 con-
fusion. Next in importance is the avoidance of the useless creation of names. Other
considerations, such as absolute grammatical correctness, regularity or euphony of
names, more or less prevailing custom, regard for persons, etc., notwithstanding
their undeniable importance, are relatively accessory.

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

The detailed provisions are divided into Rules, set out in the Articles, and
Recommendations; the notes and examples attached to these are integral parts
of them.

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.

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.

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

The Rules and Recommendations apply throughout the plant kingdom, recent
and fossil. However, special provisions are needed for certain groups. The Inter-
national Microbiological Congress has therefore issued an International Code of
Nomenclature of Bacteria and Viruses (Ames, Iowa, U.S.A., June 1958). Similarly
the International Commission for the Nomenclature of Cultivated Plants has published
an International Code of Nomenclature for Cultivated Plants (Utrecht, June 1961).
Provisions for the names of hybrids and some special categories appear in Appendix I.

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.

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

This edition of the Code supersedes all previous editions (see Bibliographia,
p. 367).

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Division I . Principles

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 assigned to the plant kingdom.*

Principle II

The application of names of taxonomic groups is determined by means of nomen-
clatural 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.

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* See Arts. 45 and 65.

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Division I I . Rules and Recommendations

Chapter I. RANKS OF TAXA, AND THE TERMS DENOTING THEM

Article 1

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

Article 2

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

Article 3

The principal ranks of taxa in ascending sequence are: species (species), genus
(genus), family (familia), order (ordo), class (classis), and division (divisio). Thus
each species belongs (is to be assigned) to a genus, each genus to a family (certain
artificial groups of fossil plants excepted), etc.

Note 1. Since the names of species, and consequently of many higher taxa, of
fossil plants are usually based on fragmentary specimens, and since the connection
between these specimens can only rarely be proved, organ-genera (organo-genera)
and form-genera (forma-genera) are distinguished as taxa within which species may
be recognized.

An organ-genus is a genus assignable to a family. A form-genus is a genus
unassignable to a family, but it may be referable to a taxon of higher rank (see
Art. 59 and Rec. 18A). Form-genera are artificial in varying degree.

Examples: Organ-genera: Lepidocarpon Scott (Lepidocarpaceae), Mazocarpon (Scott) Benson

(Sigillariaceae), Siltaria Traverse (Fagaceae); form-genera: Dadoxylon Endl. (Coniferopsida),
Pecopteris (Brongn.) Sternb. (Pteropsida), Stigmaria Brongn. (Lepidophytales and Lepido-
spermales), Spermatites Miner (Cormophyta, excl. Eocormophyta et Palaeocormophyta micro-
phylla).

Article 4

If a greater number of ranks of taxa is required, the terms for these are made
either by adding the prefix sub (sub-) 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 of the plant kingdom (Regnum Vegetabile): Divisio,
Subdivisio, Classis, Subclassis, Ordo, Subordo, Familia, Subfamilia, Tribus, Sub-
tribus, Genus, Subgenus, Sectio, Subsectio, Series, Subseries, Species, Subspecies,
Varietas, Subvarietas, Forma, Subforma.

Further supplementary ranks may be intercalated or added, provided that con-
fusion or error is not thereby introduced.

For hybrids and some special categories, see Appendix I.

Recommendation 4A

In classifying parasites, especially parasitic fungi, authors who do not give specific 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 (see Rec. 24B).

Article 5

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

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Chapter II. NAMES OF TAXA (GENERAL PROVISIONS)

Section 1. DEFINITIONS

Article 6

Effective publication is publication in accordance with Arts. 29—31.

Valid publication of names is publication in accordance with Arts. 32—45.

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

An illegitimate name or epithet is one that is contrary to the rules.

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).

Note. In this Code, unless otherwise indicated, the word “name” means a name
that has been validly published, whether it is legitimate or illegitimate.

Example: The generic name Cashalia Standl. (Journ. Wash. Acad. Sci. 13: 440. 1923),
based on the single species C. cuscatlanica, is legitimate because it is in accordance with the
rules. The same is true of the generic name Dussia Krug et Urban ex Taub. (in Engl. et
Prantl, Nat. Pflanzenfam. III. 3: 193. 1892), based on the single species D. martinicensis. Both
generic names are correct when the genera are thought to be separate. Steyermark (Fieldiana, Bot.
24(5): 248. 1946), however, united Cashalia Standl. and Dussia Krug et Urban in a
single genus; when this concept is accepted the latter name is the only correct one for the
genus with this particular circumscription. The legitimate name Cashalia may therefore be
correct or incorrect according to different concepts of taxa.

Section 2. TYPIFICATION

Article 7

The application of names of taxa of the rank of family or below is determined by
means of nomenclatural types. A nomenclatural type (typus) is that constituent element
of a taxon to which the name of the taxon is permanently attached, whether as a
correct name or as a synonym.

Note 1. The nomenclatural type is not necessarily the most typical or representative
element of a taxon; it is merely that element with which the name is permanently
associated.

Note 2. 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.

Note 3. 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 originally cited material is extant, a
neotype may be selected.

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A lectotype is a specimen or other element selected from the original material
to serve as a nomenclatural type when no holotype was designated 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 infra-specific name (e.g. male and female, flowering and fruiting, etc.),
the lectotype must be chosen from among them.

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.

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.

A neotype is a specimen or other element selected to serve as nomenclatural type
as long as all of the material on which the name of the taxon was based is missing.*

Note 4. A new name or epithet published as an avowed substitute (nomen novum)
for an older name or epihet is typified by the type of the oldest name.

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

Note 5. The typification of names of genera based on plant megafossils and
plant microfossils (form- and organ-genera), genera of imperfect fungi, and any
other analogous genera or lower taxa does not differ from that indicated above.

Note 6. 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 publication
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.

Note 7. 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 first valid pub-
lication (see Arts. 32-45). 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.

Note 8. A change of the listed type-species 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.

Example: Bullock and Killick (Taxon 6: 239. 1957) proposed, in the interests of stability
and taxonomic accuracy, that the type-species of Plectranthus L’Hér. should be changed
from P. punctatus (L.f.) L’Hér. to P. fruticosus L’Hér. This was approved by the appropriate
Committees and sanctioned by an International Botanical Congress.

Recommendation 7A

It is strongly recommended that the original material, especially the holotype, of a taxon
be deposited in a permanent responsible institution and that it be scrupulously conserved.
When living material is designated as a type (for Bacteria and Fungi only; see Art. 9, Note 3),
appropriate parts of it should be immediately preserved.

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Recommendation 7B

Whenever the original material of a taxon is heterogeneous, the lectotype should be so
selected as to preserve current usage unless another element agrees better with the original
description and (or) figure.

Recommendation 7C

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.

Article 8

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, or if it can be shown that the choice was based
upon a misinterpretation of the original description.

Article 9

The nomenclatural type (holotype, lectotype, or neotype) of a species or taxon
below the rank of species 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 and
assembled on one herbarium sheet or preparation.

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.

Examples: The holotype of the polygamous species Rheedia kappleri Eyma is a male
specimen collected by Kappler (593a in Herb. Utrecht). The author designated a herma-
phroditic specimen collected by the Forestry Service of Suriname as a paratype* (B.W. 1618
in Herb. Utrecht).

The type sheet of Tillandsia bryoides Griseb. ex Baker (Journ. of Bot. 16: 236. 1878) is
Lorentz no. 128 in Herb. Mus. Brit.; this sheet, however, proves to be a mixture. L. B. Smith
(Proc. Am. Acad. 70: 192. 1935) acted in accordance with this rule in designating one
element of Lorentz’s specimen as the lectotype.

Note 1. For the name of a species or infraspecific taxon of recent plants of
which it is impossible to preserve a specimen, or for such a name without a type
specimen, the type may be a description or figure.

Note 2. 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 coalball plants, etc.), all parts originally used in establishing
the diagnosis ought to be clearly marked.

Note 3. A type specimen of a taxon of recent plants, the Bacteria and Fungi
excepted, must be conserved permanently and cannot be a living plant or culture.

Article 10

The nomenclatural type of a genus or of any taxon between genus and species
is a species, that of a family or of any taxon between family and genus is the genus
on whose present or former name that of the taxon concerned is based (see also
Art. 18).

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* See: Guide for the determination of types (p. 64).

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Note 1. The nomenclatural type of a family not based on a generic name is the
genus that typifies the alternative name of that family (see Art. 18).

Note 2. The principle of typification does not apply to names of taxa above
the rank of family (see Art. 16).

Section 3. PRIORITY

Article 11

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 for which alternative names are permitted (see Art. 18) and for certain
fungi and fossil plants (see Art. 59).

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 con-
servation (see Arts. 14 and 15).

For any taxon below the rank of genus, the correct name is the combination of
the earliest available legitimate epithet in the same rank with the correct name of
the genus, species, or taxon of lower rank to which it is assigned.

The principle of priority does not apply to names of taxa above the rank of
family (see Art. 16).

Note. The name of a taxon below the rank of genus, consisting of the name of
a genus combined with one or more epithets, is termed a combination.

Examples of combinations: Gentiana lutea, Gentiana tenella var. occidentalis, Equisetum
palustre var. americanum f. fluitans, Mouriri subg. Pericrene, Arytera sect. Mischarytera.

Article 12

A name of a taxon has no status under this Code unless it is validly published
(see Chapter IV, section 2, Arts. 32—45).

Section 4. LIMITATION OF THE PRINCIPLE OF PRIORITY

Article 13

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):

Recent plants

a. SPERMATOPHYTA and PTERIDOPHYTA, 1 May 1753 (Linnaeus, Species Plantarum
ed. 1).

b. MUSCI (the SPHAGNACEAE excepted), 1 Jan. 1801 (Hedwig, Species Muscorum).

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

d.   LICHENES, 1 May 1753 (Linnaeus, Species Plantarum ed. 1). For nomenclatural
      purposes names given to lichens shall be considered as applying to their fungal
      components.

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e. FUNGI: UREDINALES, USTILAGANALES and GASTEROMYCETES, 31 Dec. 1801 (Per-
soon, Synopsis Methodica Fungorum).

f.   FUNGI CAETERI, 1 Jan. 1821 (Fries, Systema Mycologicicum vol. 1). Vol. 1 of the
      Systema is treated as having appeared on 1 Jan. 1821, and the Elenchus Fungorum
      (1828) is treated as a part of the Systema. Names of FUNGI CAETERI published in
      other works between the dates of the first (vol. 1) and last (vol. 3, part 2 and
      index) parts of the Systema which are synonyms or homonyms of names of any
      of the FUNGI CAETERI included in the Systema do not affect the nomenclatural
      status of names used by Fries in this work.

g.   ALGAE, 1 May 1753 (Linnaeus, Species Plantarum ed. 1). Exceptions:
      NOSTOCACEAE HOMOCYSTEAE, 1892—93 (Gomont, Monographie des Oscillariées,
      Ann. Sci. Nat. Bot. VII. 15: 263—368; 16: 91—264).
      NOSTOCACEAE HETEROCYSTEAE, 1886—88 (Bornet et Flahault, Revision des Nosto-
      cacées hétérocystées, Ann. Sci. Nat. Bot. VII. 3: 323—381; 4: 343—373; 5:
      51—129; 7: 177—262).
      DESMIDIACEAE, 1848 (Ralfs, British Desmidieae).
      OEDOGONIACEAE, 1900 (Hirn, Monographie und Iconographie der Oedogoniaceen,
      Acta Soc. Sci. Fenn. 27(1)).

h. MYXOMYCETES, 1 May 1753 (Linnaeus, Species Plantarum ed. 1).

i.    BACTERIA, 1 May 1753 (Linnaeus, Species Plantarum ed. 1). The names of
      bacteria are subject to provisions of the International Code of Nomenclature of
      Bacteria and Viruses.

Fossil plants

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

Note 1. It is agreed to associate generic names which first appear in Linnaeus’
Species Plantarum ed. 1 (1753) and ed. 2 (1762—63) with the first subsequent
description given under those names in Linnaeus’ Genera Plantarum ed. 5 (1754)
and ed. 6 (1764) (see Art. 41).

Note 2. 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).

Example: 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.

Article 14

In order to avoid disadvantageous changes in the nomenclature of genera, families,
and intermediate taxa 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 con-
servanda) and must be retained as exceptions. These names are preferably such as
have come into general use in the fifty years following their publication, or which
have been used in monographs and important floristic works up to the year 1890
(see Rec. 50E).

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Note 1. These lists of conserved names will remain permanently open for addi-
tions. 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.

Note 2. The application of both conserved and rejected names is determined
by nomenclatural types.

Note 3. A conserved name is conserved against all other names in the same rank
for the same type (nomenclatural synonyms) whether these are cited in the corres-
ponding list of rejected names or not, and against those names based on different
types that are cited in that list. 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.

Examples: If the genus Weihea Spreng. (1825) is united with Cassipourea Aubl. (1775),
the combined genus will bear the prior name Cassipourea, although Weihea is conserved

and Cassipourea is not. — If Mahonia Nutt. (1818) is united with Berberis L. (1753) the
combined genus will bear the prior name Berberis, although Mahonia is conserved. —

Nasturtium R. Br. (1812) was conserved only in the restricted sense, for a monotypic genus
based on N. officinale R. Br.; hence, if it is reunited with Rorippa Scop. (1760), it must
bear the name Rorippa.

Note 4. When a name of a genus has heen 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 genus distinct from that of the nomen conservandum.

Example: The generic name Luzuriaga Ruiz et Pav. (1802) is conserved against the earlier
names Enargea Banks et Sol. ex Gaertn. (1788) and Callixene Comm. ex Juss. (1789). If,
however, Enargea Banks et Sol. ex Gaertn. is considered to be a separate genus, the name
Enargea is retained for this.

Note 5. A conserved name is conserved against all its earlier homonyms.

Example: The generic name Smithia Ait. (1789), conserved against Damapana Adans.,
is thereby conserved automatically against the earlier homonym Smithia Scop. (1777).

Note 6. Provision for the conservation of a name in a sense that excludes the
original type is made in Art. 48.

Article 15

When a name proposed for conservation has bee n approved by the General
Committee after study by the Committee for the taxonomic group concerned, botanists
are authorized to retain it pending the decision of a later International Botanical
Congress.

Recommendation 15A

When a name proposed for conservation has been referred to the appropriate Committee
for study, botanists should follow existing usage as far as possible pending the General
Committee’s recommendation on the proposal.

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Chapter III. NOMENCLATURE OF TAXA ACCORDING TO THEIR RANK

Section 1. NAMES OF TAXA ABOVE THE RANK OF FAMILY

Article 16

The principles of priority and typification do not affect the form of names of
taxa above the rank of family (see Arts. 10 and 11).

Recommendation 16A

(a) The name of a division is preferably taken from characters indicating the nature of
the division as closely as possible; it should end in -phyta, except when it is a division of
FUNGI, in which case it should end in -mycota. Words of Greek origin are generally
preferable.

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 ending -phytina, except when it
is a subdivision of FUNGI, in which case it should end in -mycotina.

(b) The name of a class or of a subclass is formed in a similar manner and should
end as follows:

1. In the ALGAE: -phyceae (class) and -phycidae (subclass);

2. In the FUNGI: -mycetes (class) and -mycetidae (subclass);

3. In the CORMOPHYTA: -opsida (class) and -idae (subclass).

Article 17

If the name of an order is based on the stem of a name of a family, it must have
the ending -ales. If the name of a suborder is based on the stem of a name of a family,
it must have the ending -ineae.

Note 1. Names published with their rank denoted by a term such as “Cohors”,
“Nixus”, “Alliance”, or “Reihe” instead of ordo are treated as having been published
as names of orders.

Note 2. When the name of an order or suborder based on the stem of a name
of a family has been published with an improper termination, the ending must be
changed to accord with the rule, without change of the author’s name.

Examples of names of orders: Fucales, Polygonales, Centrospermae, Parietales, Farinosae,
Ustilaginales; suborders: Enantioblastae, Bromeliineae, Malvineae.

Section 2. NAMES OF FAMILIES AND SUBFAMILIES,

TRIBES AND SUBTRIBES

Article 18

The name of a family is a plural adjective used as a substantive; it is formed by
adding the suffix -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 composition, see
Rec. 73G.)

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Names published with their rank denoted by the term ordo (order, ordre, Ordnung)
instead of familia are treated as having heen published as names of families.

Examples: Rosaceae (from Rosa), Salicaceae (from Salix), Plumbaginaceae (from Plumbago),
Caryophyllaceae, nom. cons. (from Caryophyllus Mill. non L.), Winteraceae, nom. cons. (from
Wintera Murr., an illegitimate synonym of Drimys J. R. et G. Forst.).

Note 1. A name of a family based on the stem of an illegitimate generic name is
illegitimate unless conserved. Contrary to Art. 32(2) such a name is validly published
if it complies with the other requirements for valid publication.

Note 2. When a name of a family has been published with an improper Latin
termination, the ending must be changed to accord with the rule, without change
of the author’s name.

Note 3. The following names, sanctioned by long usage, are treated as exceptions
to the rule: Palmae (Arecaceae; type, Areca L.); Gramineae (Poaceae; type,
Poa L.); Cruciferae (Brassicaceae; type, Brassica L.); Leguminosae (Fabaceae;
type, Faba Mill. (= Vicia L. p.p.)); Guttiferae (Clusiaceae; type, Clusia L.);
Umbelliferae (Apiaceae; type, Apium L.); Labiatae (Lamiaceae; type, Lamium L.);
Compositae (Asteraceae; type, Aster L.).

Botanists are authorized, however, to use as alternatives the appropriate names
ending in -aceae.

When Papilionaceae are regarded as a family distinct from the remainder of the
Leguminosae, that name is conserved against Leguminosae. The alternative name is
Fabaceae. This is an unique exception to Art. 51.

Recommendation 18A

Names of families of fossil plants should not be based on names of form-genera (see Art. 3).

Article 19

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

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

The name of any taxon of a rank below family and above genus which includes
the type of the next higher taxon must be based on the same stem as the name of
the next higher taxon, but without citation of an author’s name (see Art. 46).

Examples of names of subfamilies: Asphodeloideae (from Asphodelus), Rumicoideae (from
Rumex); tribes: Asclepiadeae (from Asclepias), Phyllantheae (from Phyllanthus); subtribes:
Rutinae (from Ruta), Madiinae (from Madia).

Note. When a name of a taxon belonging to one of the above categories has
been published with an improper termination, such as -eae for a subfamily or
-oideae for a tribe, the ending must be changed to accord with the rule, without
change of the author’s name. However, when the rank of the group is changed by
a later author, his name is then cited as author for the name with the appropriate
ending, in the usual way.

Example: The subfamily name Climacieae Grout (Moss Fl. N. Am. 3: 4. 1928) must be
changed to Climacioideae with rank and author’s name unchanged. If it is held necessary
to change the rank of this taxon to a tribe, then the name Climacieae must be used followed
by the name of the author making the change.

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Section 3. NAMES OF GENERA AND SUBDIVISIONS OF GENERA*

Article 20

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.

Examples: Rosa, Convolvulus, Hedysarum, Bartramia, Liquidamar, Gloriosa, Impatiens,
Rhododendron, Manihot, Ifloga (an anagram of Filago).

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 was accompanied, when
originally published, by a specific name published in accordance with the binary
method of Linnaeus.

Examples: The generic name Radicula Hill (Brit. Herbal 264. 1756) coincides with the
technical term radicula (radicle) and, when originally published, was not accompanied by a
specific name in accordance with the Linnaean method. The name must be attributed to
Moench (Meth. 262. 1794), who first combined it with specific epithets, but at that time he
included in the genus the type-species of the generic name Rorippa Scop. (Fl. Carn. 520. 1760).

Radicula Moench must therefore be rejected in favour of Rorippa. — Tuber Michelli ex Fr.

(Syst. Myc. 2: 289. 1823) was accompanied by binary specific names, e.g. Tuber cibarium,
and is therefore admissible. — Names such as Radix, Caulis, Folium, Spina, etc., cannot now
be validly published as new generic names.

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

Example: The generic name Uva ursi Mill. (Gard. Dict. Abr. ed. 4. 1754) as originally
published consisted of two separate words unconnected by a hyphen, and must therefore be
rejected; the name must be attributed to Duhamel (Traité Arbr. Arbust. 2: 371. 1755) as
Uva-ursi (hyphened when published). However, names such as Quisqualis (formed by
combining two words into one when originally published), Sebastiano-Schaueria, and Neves-
Armondia (both hyphened when originally published) are admissible.

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

(1) words not intended as names;

Examples: Anonymos Walt. (Fl. Carol. 2, 4, 9, etc. 1788) must be rejected as being a word

applied to 28 different genera by Walter to indicate that they were without names. —
Schaenoides and Scirpoides, used by Rottböll (Descr. Pl. Rar. Progr. 14, 27. 1772) to indicate
unnamed genera resembling Schoenus and Scirpus which he stated (op. cit.: 7) he intended
to name later are token words and not generic names. Kyllinga Rottböll and Fuirena Rottböll
(Descr. Ic. Nov. Pl. 12, 70. 1773) are the first legitimate names of these genera.

(2) unitary designations of species.

Examples: F. 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 must 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

—————————

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

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name by A. Dietrich (Sp. Pl. 2(2): 89. 1833). — N. J. de 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., Fl.
Tell. 3: 25. 1837 (non Nuttall 1818).

Recommendation 20A

Botanists who are 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 tongue.

(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 taxon.

(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).

Recommendation 20B

It is desirable that the name of an organ-genus of fossil plants should indicate the morpho-
logical category of the organ (for leaves a combination with phyllum, for fructifications
with carpus or theca, etc.).

Recommendation 20C

When naming an organ-genus or a form-genus of fossil plants of uncertain nature or
affinities, a name suggesting definite relationship with a recent plant should be avoided.

Article 21

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

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.

The epithet of a subgenus or section must not be formed from the name of the
genus to which it belongs by adding the ending -oides or -opsis, or the prefix Eu-.

Examples: Costus subg. Metacostus; Ricinocarpos sect. Anomodiscus; Sapium subsect.
Patentinervia; Euphorbia sect. Tithymalus subsect. Tenellae.

Recommendation 21A

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 is placed
in parentheses between the two; when necessary, its rank is also indicated.

Examples: Astragalus (Cycloglottis) contortuplicatus; Loranthus (sect. Ischnanthus)
gabonensis.

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Recommendation 21B

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.

Botanists, 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 those
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.

If it is desired to indicate the resemblance of a subgenus or section (other than the type
subgenus or section) of one genus to another genus, the ending -oides or -opsis may be added
to the name of that other genus to form the epithet of the subgenus or section concerned.

Article 22

The subgenus or section including the type species of the correct name of the
genus to which it is assigned bears that name unaltered as its epithet, but without
citation of an author’s name (see Art. 46).

Similarly, a section including the type species of any subgenus must bear as its
epithet the correct epithet of the subgenus.

Valid publication of a name for a subgenus or section which does not include the
nomenclatural type of the next higher taxon automatically establishes another
subgenus or section which has as its type the type of this higher taxon and which
bears the generic name (or subgeneric epithet) unaltered as its epithet.

Examples: The subgenus of Croton L. containing the lectotype of the genus (C. tiglium L.)
must be called Croton subg. Croton and not Croton subg. Eluteria Griseb.

The section of the genus Mouriri Aubl. containing the type species of the subgenus
Taphroxylon Morley (M. acutiflora Naudin) must be called Mouriri subg. Taphroxylon Morley
sect. Taphroxylon and not Mouriri sect. Acutiflos Morley.

Section 4. NAMES OF SPECIES

Article 23

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 must either be united or hyphened. An epithet not so joined when
originally published is not to be rejected but, when used, must be united or hyphened.

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

Examples: Cornus sanguinea, Dianthus monspessulanus, Papaver rhoeas, Uromyces fabae,
Fumaria gussonei, Geranium robertianum, Embelia sarasinorum, Atropa bella-donna, Impatiens
noli-tangere, Adiantum capillus-veneris, Spondias mombin (an indeclinable epithet).

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

Examples: Scandix pecten ♀ L. must be transcribed as Scandix pecten-veneris; Veronica
anagallis ∇ L. must be transcribed as Veronica anagallis-aquatica.

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

Examples: Linaria linaria, Nasturtium nasturtium-aquaticum.

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The specific epithet, when adjectival in form and not used as a substantive,
agrees grammatically with the generic name.

Examples: Helleborus niger, Brassica nigra, Verbascum nigrum; Rubus amnicola, the
specific epithet being an invariable Latin substantive; Peridermium balsameum Peck, but also
Gloeosporium balsameae J. J. Davis, both from Abies balsamea, the specific epithet of which
is treated as a substantive in the second example.

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

(1) words not intended as names,

Examples: Viola “qualis” Krocker (Fl. Siles. 2: 512, 517. 1790); Atriplex “nova” Winterl
(Ind. Hort. Bot. Univ. Pest. fol. A. 8, recto et verso, 1788), the word “nova” being here used
in connection with four different species of Atriplex.

(2) ordinal adjectives used for enumeration,

Examples: Boletus vicesimus sextus, Agaricus octogesimus nonus.

(3) those published in works in which the Linnaean system of binary nomen-
clature for species was not consistently employed.

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

Linnaeus is regarded as having used binary nomenclature for species consistently
from 1753 onwards, although there are exceptions, e.g. Apocynum fol. androsaemi L.
(Sp. Pl. 213. 1753).

Recommendation 23A

Names of men and women and also of countries and localities used as specific epithets may
be substantives in the genitive (clusii, saharae) or adjectives (clusianus, dahuricus).

It will be well, in the future, to avoid the use of the genitive and the adjectival form of
the same word to designate two different species of the same genus; for example, Lysimachia
hemsleyana Maxim. (1891) and L. hemsleyi Franch. (1895).

Recommendation 23B

In forming specific epithets, botanists 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.

(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 have approved
           publication.

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

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Section 5. NAMES OF TAXA BELOW THE RANK OF SPECIES

(INFRASPECIFIC TAXA)

Article 24

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

Infraspecific epithets such as typicus, originalis, originarius, genuinus, verus, and
veridicus, purporting to indicate the taxon containing the nomenclatural type of
the next higher taxon, are illegitimate except where they repeat the specific epithet
because Art. 26 requires their use.

The use of a binary combination for an infraspecific taxon is not admissible.

Examples: Andropogon ternatus subsp. macrothrix (not Andropogon macrothrix); Herniaria
hirsuta var. diandra (not Herniaria diandra); Trifolium stellatum forma nanum (not nana).
Names published in the form of e.g. Andropogon ternatus subsp. A. macrothrix are to be
altered to the proper form without change of author’s name.

It is permissible to cite more complicated names as ternary combinations, provided
that the rank of the taxon is stated.

Examples: Saxifraga aizoon subforma surculosa Engler & Irmscher is permissible for Saxifraga
aizoon var. aizoon subvar. brevifolia forma multicaulis subforma surculosa Engler & Irmscher.

Infraspecific taxa within different species may bear the same epithets, and those
within one species may bear the same epithets as other species (but see Rec. 24C).

Examples: 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. 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.

Examples: Erysimum hieraciifolium subsp. strictum var. longisiliquum and E. hieraciifolium
subsp. pannonicum var. longisiliquum.

Recommendation 24A

Recommendations made for specific epithets (see Recs. 23A, B) apply equally to infra-
specific epithets.

Recommendation 24B

Special forms (formae speciales) are preferably named after the host species; if desired,
epithets formed of two words joined by a hyphen may be used.

Examples: Puccinia hieracii f. sp. villosi; Pucciniastrum epilobii f. sp. abieti-chamaenerii.

Recommendation 24C

Botanists proposing new infraspecific epithets should avoid those previously used for
species in the same genus.

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Article 25

For nomenclatural purposes, a species or any taxon below the rank of species
is regarded as the sum of its subordinate taxa, if any.

Valid publication of a name of a subordinate taxon which does not include the
nomenclatural type of the higher taxon automatically establishes a second taxon of
the same rank which has as its nomenclatural type the type of the higher taxon
(see Art. 26) and bears the same epithet.

Example: The publication in 1843 of Lycopodium inundatum L. var. bigelovii Tuckerm.
automatically establishes another variety, Lycopodium inundatum L. var. inundatum, the type
of which is that of Lycopodium inundatum L.

Article 26

In the name of an infraspecific taxon which includes the nomenclatural type of
the epithet of the next higher taxon, the epithet of this higher taxon must be repeated
unaltered but without citation of an author’s name (see Art. 46). This epithet can no
longer be used if that of the next higher taxon is changed.

Examples: The combination Lobelia spicata Lam. var. originalis McVaugh, which includes
the type of Lobelia spicata Lam., must be replaced by Lobelia spicata Lam. var. spicata.

Because under Lobelia syphilitica L. there is described var. ludoviciana A. DC., one must
write Lobelia syphilitica L. var. syphilitica if only that part of L. syphilitica L. which includes
the type is meant.

Because under Vochysia rufa Mart. subsp. sericea (Pohl) Stafleu there is described a variety
fulva Stafleu, one must write Vochysia rufa Mart. subsp. sericea (Pohl) Stafleu var. sericea
if only that part of the subsp. sericea (Pohl) Stafleu which includes the type is meant.

Article 27

An infraspecific epithet may repeat unchanged that of the next higher taxon only
when it has the same nomenclatural type.

Section 6. NAMES OF PLANTS IN CULTIVATION

Article 28

Plants brought into cultivation from the wild which differ in no fundamental way
from the parent stocks bear the same names as are applied to the same species and
infraspecific taxa in nature.

Plants arising in cultivation through hybridization, mutation, or other processes
which tend to establish recognizable differences from the parent stocks receive
epithets, preferably in common language (i.e. fancy epithets), markedly different
from the Latin epithets of species or varieties.

Detailed regulations for the nomenclature of plants in cultivation appear in the
International Code of Nomenclature for Cultivated Plants.

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Chapter IV. EFFECTIVE AND VALID PUBLICATION

Section 1. CONDITIONS AND DATES OF EFFECTIVE PUBLICATION

Article 29

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

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

Note. 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.

Examples: Effective publication without printed matter: Salvia oxyodon Webb et Heldr.
was published in July 1850 in an autograph catalogue placed on sale (Webb et Heldreich,
Catalogus Plantarum Hispanicarum . . . . . . ab A. Blanco lectarum, Paris, July 1850, folio).

Effective publication in reproduced handwritten material: H. Léveillé, Flore du Kouy
Tchéou (1914-15), a work lithographed from the handwritten manuscript.

Non-effective publication at a public meeting: 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.

Publication on or after 1 Jan. 1953 of a new name in tradesmen’s catalogues or
in non-scientific newspapers, even if accompanied by a Latin diagnosis, does not
constitute effective publication.

Recommendation 29A

Authors are urged to avoid publishing new names or descriptions in ephemeral publications,
in popular periodicals, in any publication unlikely to reach the general botanical public, in
those produced by such methods that their permanence is unlikely, or in abstracting journals.

Article 30

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.

Example: Individual parts of Willdenow’s Species Plantarum were published as follows:
1(1), 1797; 1(2), 1798; 2(1), 1799; 2(2), 1799 or 1800; 3(1) (to page 850), 1800; 3(2) (to page
1470), 1802; 3(3) (to page 2409), 1803 (and later than Michaux’ 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 the dates of publication (see Rhodora 44: 147-150. 1942).

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 publication
unless there is evidence that it is erroneous.

Example: Publication in separates issued in advance: 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.

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Recommendation 30A

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 publication.

Article 31

The distribution on or after 1 Jan. 1953 of exsiccata relative to any new taxon,
accompanied by an original diagnosis, even if this is printed, does not constitute
effective publication.

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

Example: Works such as Schedae operis . . . ., Plantae Finlandiae Exsiccatae, Helsingfors
1. 1906, 2. 1916, 3. 1933, 1944, or Lundell et Nannfeldt, Fungi Exsiccati Suecici etc., Uppsala
1-. . . ., 1934-. . . ., whether published before or after 1 Jan. 1953, are effectively published.

Section 2. CONDITIONS AND DATES OF VALID PUBLICATION OF NAMES

Article 32

In order to be validly published, a name of a taxon must (1) be effectively
published (see Art. 29), (2) have a form which complies with the provisions of
Chapter III (but see Art. 18, notes 1 and 2), and (3) be accompanied by a description
of the taxon or by a reference (direct or indirect) to a previously and effectively
published description of it.

Note 1. 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 description
applies to the taxon to which the new name is given.

Examples of names not validly published: Egeria Néraud (in Gaudichaud, Bot. Voy.
Freycinet 28. 1826), published without a description or a reference to a former description. —

The name Loranthus macrosolen Steud. originally appeared without a description on the
printed tickets issued about the year 1843 with Sect. II. no. 529, 1288, of Schimper’s her-
barium specimens of Abyssinian plants; it was not validly published, however, until A. Richard
(Tent. Fl. Abys. 1: 340. 1847) supplied a description.

Examples of indirect reference: — Kratzmannia Opiz (in Berchtold et Opiz, Oekon.-techn.
Fl. Böhmens 1/2: 398. 1836) is published with a description, but it was not definitely accepted
by the author and is therefore not validly published. It is accepted definitely in Opiz, Seznam
Rostlin Květeny České 56 (1852), but without any description. The citation of “Kratzmannia

O.” includes an indirect reference to the previously published description in 1836. — Opiz
published the name of the genus Hemisphace (Benth.) Opiz in Seznam Rostlin Květeny České
50 (1852) without a description, but as he wrote Hemisphace Benth. he indirectly referred
to the previously validly published description by Bentham, Labiat. Gen. Sp. 193 (1833), of

Salvia sect. Hemisphace. — The publication of the new combination Cymbopogon martinii
by W. Watson in Atkinson, Gaz. NW. Provo India 10: 392 (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 synonym Andropogon martini is indirect, it is perfectly unambiguous.

Note 2. In certain circumstances an illustration with analysis is accepted as
equivalent to a description (see Arts. 42 and 44).

Note 3. For names of plant taxa originally published as names of animals, see
Art. 45.
33

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Recommendation 32A

Publication of a name should not be validated solely by a reference to a description
published before 1753.

Recommendation 32B

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

Recommendation 32C

Authors should avoid adoption of a name or an epithet which has been previously but
not validly published for a different taxon.

Recommendation 32D

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

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

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

Recommendation 32E

The description 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 significance of which is often
doubtful.

Article 33

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

Examples of combinations definitely indicated: In Linnaeus’ 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 other name.

Examples of combinations not definitely indicated: Rafinesque’s statement under Blephilia
(in Journ. Phys. Chim. Hist. Nat. 89: 98. 1819) that “Le type de ce genre est la Monarda
ciliata Linn.” 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 must not be ascribed to Bentham and Hooker f. on the basis of the listing
of Cnidium peucedanoides H.B.K. under Eulophus (Gen. Pl. 1: 885. 1867).

A new combination or a new name for a previously recognized taxon published on
or after 1 Jan. 1953 is not validly published unless its basionym (name-bringing or
epithet-bringing synonym) or replaced synonym is clearly indicated and a full and
direct reference given to its author and original publication with page or plate
reference and date.

Note 1. 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.

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Note 2. Bibliographic errors of citation do not invalidate the publication of a
new combination.

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

An exception is made for names of the infrageneric taxa termed tribes (tribus) in
Fries’ Systema Mycologicum, which are treated as validly published.

Example: The names Delphinium tribus Involuta Huth (Bot. Jahrb. 20: 365. 1895), tribus
Brevipedunculata Huth (l.c. 20: 368), etc., are treated as not validly published, since Huth
misapplied the term “tribus” to a category of lower rank than section.

Article 34

A name is not validly published (1) when it is not accepted by the author who
published it; (2) 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); (3) when it is merely mentioned incidentally;

(4) when it is merely cited as a synonym; (5) by the mere mention of the subordinate
taxa included in the taxon concerned.

Note 1. Provision no. 1 does not apply to names or epithets published with a
question mark or other indication of taxonomic doubt, yet published and accepted
by the author.

Note 2. 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.

Examples: (1) The generic name Sebertia Pierre ex Baillon (Bull. Soc. Linn. Paris 2: 945.
1891) was not accepted by Baillon who referred its only species with a question mark to the
genus Sersalisia.

(1) (2) The generic name Conophyton Haw., suggested by Haworth (Rev. Pl. Succ. 82.
1821) for Mesembryanthemum sect. Minima Haw. (l.c. 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. Brown (Gard. Chron. III. 71: 198. 1922).

(3) The generic name Jollya was mentioned incidentally by Pierre (Notes Bot. Sapot. 7.
1890) in the discussion of the stamens of another genus and was therefore not validly
published in that publication.

(4) Acosmus Desv. (in Desf. Cat. Pl. Hort. Paris ed. 3. 233. 1829), cited as a synonym of
the generic name Aspicarpa L. C. Rich., was not validly published thereby. — Ornithogalum
undulatum Hort. Bouch. ex Kunth (Enum. 4: 348. 1843), cited as a synonym under Myogalum
boucheanum Kunth, was not validly published thereby; when transferred to Ornithogalum,
this species must be called Ornithogalum boucheanum (Kunth) Aschers. (Oest. Bot. Zeitschr.
16: 192. 1866).

Similarly Erythrina micropteryx Poepp. was not validly published by being cited as a
synonym of Micropteryx poeppigiana Walp. (Linnaea 23: 740. 1850); the species concerned,
when placed under Erythrina, must be called Erythrina poeppigiana (Walp.) O. F. Cook
(U.S. Dep. Agr. Bull. 25: 57. 1901).

(5) The family name Rhaptopetalaceae Pierre (Bull. 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; the family bears
the later name Scytopetalaceae Engler (in Engler et Prantl, Nat. Pflanzenfam. Nachtr. zum

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II-IV. 1: 242. 1897), which was accompanied by a description. — 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, his publication of Ibidium
is invalid.

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.

Example: The species of Brosimum described by Ducke (Arch. Jard. Bot. Rio 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.

Recommendation 34A

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, i).

Article 35

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

Note. For such names published before 1 Jan. 1953 the choice made by the first
author who assigned a definite rank must be followed.

Article 36

In order to be validly published, a name of a new taxon of plants, the bacteria,
algae, and all fossils excepted, published on or after 1 Jan. 1935 must be accompanied
by a Latin diagnosis or by a reference to a previously and effectively published
Latin diagnosis.

Example: The names Schiedea gregoriana Degener, Fl. Hawaiiensis, fam. 119. 1936 (Apr. 9)
and S. kealiae Caum et Hosaka, Bernice P. Bishop Mus. Occas. Papers 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 diagnosis, the later
S. kealiae is the legitimate name.

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

Recommendation 36A

Authors publishing names of new taxa of recent plants should give or cite a full description
in Latin in addition to the diagnosis.

Article 37

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. 7—10).

————————

* The Nomenclature Section of the Montreal Botanical Congress adopted a resolution
recommending botanists to interpret this Article in the sense intended by the Paris Congress.
The sense of the Paris Congress was that the word “algae” applied only to recent algae.

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Recommendation 37A

The indication of the nomenclatural type should immediately follow the Latin 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

When the nomenclatural type of a new taxon is a specimen, the place where it is perma-
nently conserved should be indicated.

Article 38

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 illustra-
tion or figure showing the essential characters, in addition to the description, or by
a reference to a previously and effectively published illustration or figure.

Article 39

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

Article 40

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

Article 41

In order to be validly published, a name of a genus must be accompanied (1) by a
description of the genus, or (2) by a reference (direct or indirect) to a previously
and effectively published description of the genus in that rank or as a subdivision
of a genus.

An exception is made for the generic names first published by Linnaeus in Species
Plantarum ed. 1 (1753) and ed. 2 (1762—63), which are treated as having been
validly published on those dates (see Art. 13, Note 1).

Note. In certain circumstances, an illustration with analysis is accepted as
equivalent to a generic description (see Art. 42).

Examples of validly published generic names: Carphalea Juss. (Gen. 198. 1789), accom-
panied by a generic description; Thuspeinanta Th. Dur. (Ind. Gen. Phan. x. 1888), accompanied
by a reference to the previously described genus Tapeinanthus Boiss. (non Herb.); Aspalathoides
(DC.) K. Koch (Hort. Dendrol. 242. 1853), based on a previously described section, Anthyllis
sect. Aspalathoides DC.

Recommendation 41A

An author describing a new genus of fossil plants should indicate whether he regards it
as an organ-genus or a form-genus.

Recommendation 41B

An author describing an organ-genus should clearly indicate for which kind of organ
the genus is established.
37

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Article 42

The publication of the name of a monotypic new genus based on a new species is
validated either by (1) the provision of a combined generic and specific description
(descriptio generico-specifica), or (2), for generic names published before 1 Jan. 1908,
by the provision of an illustration with analysis showing essential characters (see
Art. 32, Note 2). However, the name of a monotypic genus of fossil plants published
on or after 1 Jan. 1953 must be accompanied by a description of the genus indicating
its difference from other genera.

Examples: Strophioblachia fimbricalyx Boerl. (Handl. Fl. Ned. Ind. 3(1): 235. 1900) is a
new species assigned to the monotypic new genus Strophioblachia published with a combined
generic and specific description. — The generic name Philgamia Baill. (in Grandidier, Hist.
Madag. Pl. Atlas 3: pl. 265. 1894) was validly published, as it appeared on a plate with
analyses of P. hibbertioides Baill. published before 1 Jan. 1908.

Note 1. A description of a new species assigned to a monotypic new genus is
treated also as a generic description if the genus is not separately described.

Similarly, a description of a monotypic new genus based on a new species is
treated also as a specific description if the generic name and specific epithet are
published together and the species is not separately described.

Note 2. Single figures of microscopic plants showing the details necessary for
identification are considered as illustrations with analysis showing essential characters.

Article 43

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.

Examples: The specific names Eragrostis minor and E. major were published in 1809 by
Host (Gram. Austr. 4: 15, 14) as substitutes for Poa eragrostis L. and Briza eragrostis L.
respectively; these two names were cited as synonyms. As, however, the generic name
Eragrostis was not validly published until 1812 (P. Beauv. Agrost. 70), the names given by
Host cannot be considered validly published.

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 Krempelh.), P. brasiliensis (= Phlyctis brasiliensis Nyl.), and P. andensis
(= Phlyctis 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
diagnosis but only a description of the new species P. hampeana. This description cannot
validate the generic name as a descriptio generico-specifica in accordance with Art. 42, since
the new genus was not monotypic. The first valid publication of the name Phlyctidia was
made by Müller in 1895 (Hedwigia 34: 141), where a short generic diagnosis was given. 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. This Article applies to specific and other epithets published under Anonymos
and other words not intended as generic names (see Art. 20, Note (1)).

Examples: The binary combination Anonymos aquatica Walt. (Fl. Carol. 230. 1788) is not
validly published. The correct name for the species concerned is Planera aquatica J. F. Gmel.
(1791), and the date of the epithet aquatica for purposes of priority is 1791. The species
must not be cited as Planera aquatica (Walt.) J. F. Gmel. If, however, it is desired to indicate
that the epithet originated with Walter, the name may be cited as Planera aquatica [Walt.]
J. F. Gmel.

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The binary combination Scirpoides paradoxus Rottböll (Descr. Pl. Rar. Progr. 27. 1772)
is not validly published since Scirpoides is a word not intended as a generic name. The first
validly published name for this species is Fuirena umbellata Rottböll (Descr. Ic. Pl. 70. 1773).

Article 44

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 showing
essential characters (see Art. 32, Note 2).

Note. Single figures of microscopic plants showing the details necessary for
identification are considered as illustrations with analysis showing essential characters.

Examples: Panax nossibiensis Drake (in Grandidier, Hist. Madag. Pl. Atlas 3: pl. 406. 1896),
published on a plate with analyses. — Eunotia gibbosa Grunow (in Van Heurck, Syn. Diat.
Belg. pl. 35, fig. 13. 1881), a name of a diatom published with a single figure of the valve.

Examples of names of species not validly published are given under Arts. 33 and 34.

Article 45

The date of a name or of an epithet 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.

Example: Specimens of Mentha foliicoma Opiz were distributed by Opiz in 1832, but the
name dates from 1882, when it was validly published by Déséglise (Bull. Soc. Etud. Sci.
Angers 1881-82: 210. 1882).

Note. For purposes of priority only legitimate names and epithets are taken into
consideration (see Arts. 11, 63—67). However, validly published earlier homonyms,
whether legitimate or not, shall cause rejection of their later homonyms (unless the
latter are conserved).

If a taxon is transferred from the animal to the plant kingdom, its name or names
available* under the International Rules of Zoological Nomenclature and validly
published in the form provided in the botanical Code (except that for algae validity
under the zoological rules only is required) shall be automatically accepted as having
been validly published under this Code at the time of its valid publication as the
name of an animal.

Example: Amphiprora Ehrenberg (Abh. Preuß. Akad. Wiss. 1841: 401. 1843) was published
as the name of a genus of animals which was transferred to the plant kingdom in 1844 by
Kützing; it has priority in botanical nomenclature from 1843, not 1844.

Recommendation 45A

Authors publishing a name of a new taxon in works written in a modern language (floras,
catalogues, etc.) should simultaneously comply with the requirements of valid publication.

Recommendation 45B

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.

————————

* The word “available” in the International Rules of Zoological Nomenclature is equivalent
to “legitimate” in the International Code of Botanical Nomenclature.

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Recommendation 45C

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

Section 3. CITATION OF AUTHORS’ NAMES AND OF LITERATURE

FOR PURPOSES OF PRECISION

Article 46

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 who first validly published the name concerned unless the provisions of
Arts. 19, 22, or 26 apply.

Examples: Rosaceae Juss., Rosa L., Rosa gallica L., Rosa gallica var. eriostyla R. Keller,
Rosa gallica L. var. gallica.

Recommendation 46A

Authors’ names put after names of plants should 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).

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).

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).

Christian 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, Gaertn. f. for Gaertner
filius, R. Br. for Robert Brown, A. Br. for Alexander Braun, 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).

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, F. v. Muell.
for Ferdinand von Mueller).

Recommendation 46B

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 (&).

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.

Examples: Didymopanax gleasonii Britton et Wilson (or Britton & Wilson); Streptomyces
albo-niger Hesseltine, J. N. Porter, Deduck, Hauck, Bohonos, & J. H. Williams, Mycologia 46:
19. 1954, should be cited as S. albo-niger Hesseltine et al.

Recommendation 46C

When a name has been proposed but not validly published by one author and is sub-
sequently validly published and ascribed to him by another author, the name of the former

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author followed by the connecting word ex may be inserted before the name of the publishing
author. The same holds for names of garden origin cited as “Hort.” (Hortulanorum). If it is
desirable or necessary to abbreviate such a citation, the name of the publishing author, being
the more important, should be retained.

Examples: Havetia flexilis Spruce ex Planch. et Triana or Havetia flexilis Planch. et Triana.
— Gossypium tomentosum Nutt. ex Seem. or Gossypium tomentosum Seem. — Lithocarpus
polystachya (Wall. ex A. DC.) Rehder or Lithocarpus polystachya (A. DC.) Rehder. —
Gesneria donklarii Hort. ex Hook. or Gesneria donklarii Hook.

Recommendation 46D

When a name with a description (or reference to a description) 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 is the
most important and should be retained when it is desirable to abbreviate such a citation.

Examples: Viburnum ternatum Rehder in Sargent, Trees and Shrubs 2: 37 (1907), or
Viburnum ternatum Rehder; Teucrium charidemii Sandwith in Lacaita, Cavanillesia 3: 38
(1930), or Teucrium charidemii Sandwith.

Recommendation 46E

The citation of an author who published the name before the starting-point of the group
concerned (see Art. 13) is indicated when such indication is considered useful or desirable,
preferably between square brackets.

Examples: Lupinus [Tourn. Inst. 392. pl. 213. 1719] L. Sp. Pl. 721. 1753, Gen. Pl. ed. 5. 322.
1754, or Lupinus [Tourn.] L. — Boletus piperatus [Bull. Hist. Champ. Fr. 318. pl. 451, f. 2.
1791-1812] Fr. Syst. Myc. 1: 388. 1821, or Boletus piperatus [Bull.] Fr.

Article 47

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

When the alteration mentioned in Art. 47 has been considerable, the nature of the change
and the author responsible for it may be indicated by adding such words, abbreviated where
suitable, as emendavit (emend.), 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.), etc.

Examples: Phyllanthus L. emend. Müll. Arg.; Myosotis L. pro parte, R. Br.; Globularia
cordifolia L. excl. var. (emend. Lam.).

Article 48

When an author circumscribes a taxon in such a way as to exclude the original
type of the name he uses for it, he is considered to have published a later homonym
that must be ascribed solely to him.

Example: Lemanea as treated by Sirodot (1872) explicitly excluded the type of Lemanea
Bory (1808) and hence must be cited Lemanea Sirodot and not Lemanea Bory emend. Sirodot.

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Note. Retention of a name in a sense that excludes the type can be effected only
by conservation. 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.

Example: Bulbostylis Kunth, nom. cons. (non Bulbostylis Steven 1817). — This must not
be cited as Bulbostylis Steven emend. Kunth, since the type listed was not included in
Bulbostylis by Steven in 1817.

Article 49

When a genus or a taxon of lower rank is altered in rank but retains its name or
epithet, the author who first published this as a legitimate name or epithet must
be cited in parentheses, followed by the name of the author who effected the alteration.
The same holds when a taxon of lower rank than genus is transferred to another
taxon, with or without alteration of rank.

Examples: Medicago polymorpha L. var. orbicularis L. when raised to the rank of species
becomes Medicago orbicularis (L.) All. — Anthyllis sect. Aspalathoides DC. raised to generic
rank, retaining the name Aspalathoides, is cited as Aspalathoides (DC.) K. Koch.

Sorbus sect. Aria Pers. on transference to Pyrus is cited as Pyrus sect. Aria (Pers.) DC. —
Cheiranthus tristis L. transferred to the genus Matthiola becomes Matthiola tristis (L.) R. Br.

The species of Corydalis based on Fumaria bulbosa γ solida L. (1753) must be cited as
Corydalis solida (L.) Sw. (1819) and not as Corydalis solida (Mill.) Sw. The latter citation
refers to Fumaria solida (L.) Mill. from 1771, also based on Fumaria bulbosa γ solida L.;
the former, correct citation refers to the first author of the legtimate epithet.

Article 50

When the status of a taxon bearing a binary name is altered from species to hybrid
or vice versa, the name of the original author must be cited, followed by an indication
in parentheses of the original status. If it is desirable or necessary to abbreviate such
a citation, the indication of the original status may be omitted.

Examples: Stachys ambigua J. E. Smith. (Engl. Bot. 30: pl. 2089. 1810) was published as
a species. If regarded as a hybrid, it must be cited as Stachys × ambigua J. E. Smith (pro

sp.). — The binary name Salix × glaucops Anderss. in DC. (Prodr. 16(2): 281. 1868) was
published as the name of a hybrid. Later, Rydberg (Bull. New York Bot. Gard. 1: 270. 1899)
altered the status of the group to that of a species. If this view is accepted, the name must be
cited as Salix glaucops Anderss. (pro hybr.).

Section 4. GENERAL RECOMMENDATIONS ON CITATION

Recommendation 50A

In the citation of a name published as a synonym, the words “as synonym” or pro syn.
should be added.

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.

Example: 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, Nomencl.
321 (1821) pro syn.

Recommendation 50B

In the citation of a nomen nudum, its status should be indicated by adding nomen nudum
(nom. nud.).

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Recommendation 50C

When a name that is illegitimate because of an earlier homonym is cited in synonymy, the
citation 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 later homonym, preceded by the word nec.

Examples: Ulmus racemosa Thomas, Am. Journ. Sci. 19: 170 (1831) non Borkh. 1800. —
Lindera Thunb. Nov. Gen. Pl. 64 (1783) non Adans. 1763. — Bartlingia Brongn. Ann. Sci.
Nat. 10: 373 (1827) non Reichb. 1824. nec F. v. Muell. 1877.

Recommendation 50D

Misidentifications should not be included in the synonymy but added after it. A misapplied
name should be indicated by the words auct. non followed by the name of the original author
and the bibliographical reference of the misidentification.

Examples: Ficus stortophylla Warb. in Warb. et De Wild. Ann. Mus. Congo Belge Bot. VI.
1: 32 (1904). F. irumuensis De Wild. Pl. Bequaert. 1: 341 (1922). F. exasperata auct. non Vahl:
De Wild. et Th. Dur. Ann. Mus. Congo Belge Bot. II. 1: 54. 1899; De Wild. Pl. Laur. 26
(1903); Th. et H. Dur. Syll. Fl. Congol. 505 (1909).

Recommendation 50E

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

Examples: Protea L. Mant. 187 (1771), nom. cons., non L. 1753. — Combretum Loefl.
1758 nom. cons. (syn. prius Grislea L.). — Schouwia DC. nom. cons. (homonymum prius
Schouwia Schrad.).

Recommendation 50F

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.

Examples: Pyrus calleryana Decne. (Pirus mairei Léveillé, Repert. Sp. Nov. 12: 189. 1913)
or (P. mairei Léveillé, Repert. Sp. Nov. 12: 189. 1913, “Pirus”), but not as Pyrus mairei.

Zanthoxylum cribrosum Spreng. Syst. 1: 946. 1825, “Xanthoxylon” (Xanthoxylum caribaeum
var. floridanum (Nutt.) A. Gray, Proc. Am. Acad. II. 23: 225. 1888), but not as Z. caribaeum var.
floridanum (Nutt.) A. Gray.

Quercus bicolor Willd. (Q. prinus discolor Michx. f. Hist. Arb. For. 2: 46. 1811), but not as
Q. prinus var. discolor Michx. f.

Spiraea latifolia (Ait.) Borkh. (Spiraea salicifolia γ latifolia Ait. Hort. Kew. 2: 198. 1789),
but not as S. salicifolia latifolia Ait. or S. salicifolia var. latifolia Ait.

Juniperus communis var. saxatilis Pallas (J. communis [var.] 3 nana Loudon, Arb. Brit. 4:
2489. 1838). In this case “var.” may be added in brackets, since Loudon classes this comb-
ination under “varieties”.

Ribes tricuspis Nakai, Bot. Mag. Tokyo 30: 142. 1916, “tricuspe”.

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Chapter V. RETENTION, CHOICE, AND REJECTION OF NAMES

Section 1. RETENTION OF NAMES OR EPITHETS OF TAXA

WHICH ARE REMODELLED OR DIVIDED

Article 51

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 (1) by transference
of the taxon (Arts. 54—56), or (2) by its union with another taxon of the same rank
(Arts. 57, 58, Rec. 57A), or (3) by a change of its rank (Art. 60).

An unique exception is made for the family name Papilionaceae (see Art. 18, Note 3).

Examples: 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 must be cited as Myosotis L. or as Myosotis L.

emend. R. Br. (see Art. 47, Rec. 47A). — Various authors have united with Centaurea jacea
L. one or two species which Linnaeus had kept distinct; the taxon so constituted must be
called Centaurea jacea L. sensu amplo or Centaurea jacea L. emend. Cosson et Germain,
emend. Visiani, or emend. Godr., etc.; the creation of a new name such as Centaurea vulgaris
Godr. is superfluous and illegitimate.

Article 52

When a genus is divided into two or more genera, the generic name must be
retained for one of them or, if it has not been retained, must be reinstated for one
of them. When a particular species was originally designated as the type, the generic
name must be retained for the genus including that species. When no type has
been designated, a type must be chosen (see Guide for the determination of types,
p. 64).

Examples: The genus Dicera J. R. et G. Forster (Char. Gen. Pl. 79. 1776) was divided by
Rafinesque (Sylva Tell. 60. 1838) into the two genera Misipus and Skidanthera; this procedure
is inadmissible: the name Dicera must be kept for one of the genera, and it is now retained for

that part of Dicera based on the lectotype, D. dentata. — The genus Aesculus L. contains the
sections Aesculus, Pavia (Poir.) Pax, Macrothyrsus (Spach) Pax, and Calothyrsus (Spach) Pax,
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 the species Aesculus hippocastanum L., as this species
is the type of the genus founded by Linnaeus (Sp. Pl. 344. 1753; Gen. Pl. ed. 5. 161. 1754);
Tournefort’s name Hippocastanum must not be used for a genus including Aesculus hippo-
castanum L. as was done by P. Miller (Gard. Dict. Abr. ed. 4. 1754).

Article 53

When a species is divided into two or more species, the specific epithet must be
retained for one of them or, if it has not been retained, must be reinstated for one
of them. When a particular specimen, description, or figure was originally designated
as the type, the specific epithet must be retained for the species including that
element. When no type has been designated, a type must be chosen (see Guide for
the determination of types, p. 64).

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Examples: Lychnis dioica L. (Sp. Pl. 437. 1753) was divided by Miller (Gard. Dict. ed. 8.

nos. 3, 4. 1768) into two species, L. dioica L. emend. Mill. and L. alba Mill. — G. F. Hoff-
mann (Deutschl. Fl. 1: 166. 1800) divided Juncus articulatus L. (1753) into two species,
J. lampocarpus Ehrh. ex Hoffm. and J. acutiflorus Ehrh. ex Hoffm. The name J. articulatus
L. ought, however, to have been retained for one of the segregate species, and it has been
reinstated in the sense of J. lampocarpus Ehrh. ex Hoffm. (see Briq. Prodr. Fl. Corse 1: 264.

1910). — Genista horrida (Vahl) DC. (in Lam. et DC., Fl. Franç. ed. 3. 4: 500. 1805) was
divided by Spach (Ann. Sci. Nat. Bot. III. 2: 252. 1844) into three species, G. horrida (Vahl)
DC., G. boissieri Spach, and G. webbii Spach; the name G. horrida was rightly kept for the
species including the plant from Jaca in Aragon originally described by Vahl (Symb. 1: 51.

1790) as Spartium horridum. — Two species (Primula cashmiriana Munro, P. erosa Wall.)
have been separated from Primula denticulata J. E. Smith (Exot. Bot. 2: 109. pl. 114. 1806),
but the name P. denticulata has rightly been kept for the form which Smith described and

figured under this name. — Stipa pennata L. (Sp. Pl. 1753) has been split into several species
all bearing other names. Mansfeld (Repert. Sp. Nov. 47: 268. 1939) rightly reintroduced this
name for one of the species, namely Stipa joannis Čel. (Oest. Bot. Zeitschr. 34: 318. 1884),
which must be abandoned.

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.

Section 2. RETENTION OF EPITHETS OF TAXA BELOW THE RANK OF GENUS

ON TRANSFERENCE TO ANOTHER GENUS OR SPECIES

Article 54

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, its epithet must
be retained or, if it has not been retained, must be reinstated unless one of the
following obstacles exists:

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

(2) an earlier and legitimate epithet of the same rank is available;

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

Examples: Saponaria sect. Vaccaria DC. when transferred to Gypsophila becomes Gypso-

phila sect. Vaccaria (DC.) Godr. — Primula sect. Dionysiopsis Pax when transferred to the
genus Dionysia cannot become Dionysia sect. Dionysiopsis (Pax) Melchior because of Art. 21;
the name Dionysia sect. Ariadna Wendelbo, based on the same type, has to be used instead.

Article 55

When a species is transferred to another genus or placed under another generic
name for the same genus without change of rank, the specific epithet, if legitimate,
must be retained a) or, if it has not been retained, must be reinstated b) unless
one of the following obstacles exists:

(1) the resulting binary name is a later homonym c) (Art. 64) or a tautonym d)
(Art. 23);

————————

* Here and elsewhere in this Code the phrase “subdivision of a genus” refers only to
taxa between genus and species in rank.
45

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(2) an earlier legitimate specific epithet is available e).

Examples: a) Antirrhinum spurium L. (Sp. Pl. 613. 1753) when transferred to the genus

Linaria must be called Linaria spuria (L.) Mill. (Gard. Dict. ed. 8. no. 15. 1768). — b) Spergula
stricta Sw. (1799) when transferred to the genus Arenaria must be called Arenaria uliginosa
Schleich. ex Schlechtend. (1808) because of the existence of Arenaria stricta Michx. (1803), a
different species; but on further transfer to the genus Minuartia the epithet stricta must be

reinstated and the species called Minuartia stricta (Sw.) Hiern (1899). — c) Spartium biflorum
Desf. (1798) when transferred to the genus Cytisus by Spach in 1849 could not be called
Cytisus biflorus, because this name had been previously and validly published for a different
species by L’Héritier in 1791; the name Cytisus fontanesii given by Spach is therefore legiti-

mate. — d) Pyrus malus L. (1753) when transferred to the genus Malus must be called Malus

sylvestris Mill. (1768), the combination Malus malus Britton (1913) being illegitimate. —
e) Melissa calamintha L. (1753) when transferred to the genus Thymus becomes T. calamintha
(L.) Scop. (1772); placed in the genus Calamintha it cannot be called C. calamintha (a
tautonym) but is called C. officinalis Moench (1794). However, when C. officinalis is trans-
ferred to the genus Satureja, the earlier legitimate epithet is again available and its name
becomes S. calamintha (L.) Scheele (1843).

When, on transference to another genus, the specific epithet has been applied
erroneously in its new position to a different species, the new combination must be
retained for the species to which the epithet was originally applied, and must be
attributed to the author who first published it f).

Example: f) 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.) Sargent: the com-
bination Tsuga mertensiana (Bong.) Carr. must not be applied to T. heterophylla (Raf.)
Sargent 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 epithet.

Article 56

When an infraspecific taxon is transferred without change of rank to another
genus or species, the original epithet must be retained or, if it has not been retained,
must be reinstated unless one of the following obstacles exists:

(1) the resulting ternary combination has been previously and validly published
for an infraspecific taxon based on a different type, even if that taxon is of different
rank;

(2) an earlier legitimate epithet is available;

(3) Arts. 24 or 26 provide that another epithet be used.

Example: The variety micranthum Gren. et Godr. (Fl. France 1: 171. 1847) of Helian-
themum italicum Pers. when transferred as a variety to H. penicillatum Thib. retains its
varietal epithet, becoming H. penicillatum var. micranthum (Gren. & Godr.) Grosser (Pflan-
zenreich, Heft 14 (IV. 193): 115. 1903).

When, on transference to another genus or species, the epithet of an infraspecific
taxon has been applied erroneously in its new position to a different taxon of the
same rank, the new combination must be retained for the taxon to which the original
combination was applied, and must be attributed to the author who first published it.

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Section 3. CHOICE OF NAMES WHEN TAXA OF THE SAME RANK ARE

UNITED

Article 57

When two or more taxa of the same rank are united, the oldest legitimate name
or (for taxa below the rank of genus) the oldest legitimate epithet is retained, unless
a later name or epithet must be accepted under the provisions of Art. 58. The author
who first unites taxa bearing names or epithets of the same date has the right to
choose one of them, and his choice must be followed.

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

genus. — If the two genera Dentaria L. (Sp. Pl. 653. 1753; Gen. Pl. ed. 5. 295. 1754) and
Cardamine L. (Sp. Pl. 654. 1753; Gen. Pl. ed. 5. 295. 1754) are united, the resulting genus
must be called Cardamine because the name was chosen by Crantz (Class. Crucif. 126. 1769),

who was the first to unite the two genera. — Robert Brown (in Tuckey, Narr. Exp. Congo
484. 1818) appears to have been the first to unite Waltheria americana L. (Sp. Pl. 673. 1753)
and W. indica L. (Sp. Pl. 673. 1753). He adopted the name Waltheria indica for the combined

species, and this name must accordingly be retained. — Fiori et Paoletti (Fl. Ital. 1(1): 107.
1896) united Triticum aestivum L. (Sp. Pl. 85. 1753) and T. hybernum L. (loc. cit.) into one
species under one of these names, T. aestivum L. Consequently the latter name is correct
for the combined taxon comprising common soft wheat. The use of an illegitimate name, such
as Triticum vulgare Vill. (Hist. Pl. Dauph. 2: 153. 1787), or the creation of a new name is
contrary to the Code.

Recommendation 57A

Authors who have to choose between two generic names should note the following
suggestions:

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

(2) 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.

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

Recommendation 57B

Fossil specimens uniting diagnostic features of diverse taxa may be either assigned to
one of them, thereby enlarging its circumscription, or proposed as a new taxon having the
amplified circumscription (but see Art. 63).

Article 58

When a taxon of recent plants, algae excepted, and a taxon of the same rank of
fossil or subfossil plants are united, the correct name or epithet of the recent taxon
must take precedence.

Example: If Platycarya Sieb. et Zucc. (1843), a genus of recent plants, and Petrophiloides
Bowerbank (1840), a genus of fossil plants, are united, the name Platycarya must be accepted
for the combined genus, although it is antedated by Petrophiloides.

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Section 4. NAMES OF FUNGI WITH A PLEOMORPHIC LIFE CYCLE AND

OF FOSSILS ASSIGNED TO FORM-GENERA

Article 59

In Ascomycetes and Basidiomycetes with two or more states in the life cycle (except
those which are lichen-fungi), but not in Phycomycetes, the first legitimate name or
epithet applied to the perfect state takes precedence. The perfect state is that which
bears asci in the Ascomycetes, which consists of the spores giving rise to basidia in
the Uredinales and of the chlamydospores in the Ustilaginales, or which bears basidia
in the remaining Basidiomycetes. The type specimen of a name applied to a particular
state must show the characteristics of that state. However, the provisions of this
Article shall not be construed as preventing the use of names of imperfect states in
works referring to such states. The author who first describes a perfect state may
adopt the specific epithet applied to the corresponding imperfect state, but his
binomial for the perfect state is to be attributed to him alone, and is not to be
regarded as a new combination.

When not already available, binomials for imperfect states may be proposed at
the time of publication of the name of a perfect state or later, and may contain
either the specific epithet applied to the perfect state or any other epithet available.

As in the case of pleomorphic fungi, the provisions of the Code shall not be
construed as preventing the use of names of form-genera in works referring to
such taxa.

Section 5. CHOICE OF NAMES WHEN THE RANK OF A TAXON IS CHANGED

Article 60

When the rank of a genus or infrageneric* taxon is changed, the correct name or
epithet is the earliest legitimate one available in the new rank. In no case does a
name or an epithet have priority outside its own rank.

Examples: The section Campanopsis R. Br. (Prodr. 561. 1810) of the genus Campanula
was first raised to generic rank by Schrader and, as a genus, must be called Wahlenbergia
Schrad. ex Roth (Nov. Pl. Sp. 399. 1821), not Campanopsis (R. Br.) O. Kuntze (Rev. Gen.

Pl. 2: 378. 1891). — Magnolia virginiana var. foetida L. (Sp. Pl. 536. 1753) when raised to
specific rank must be called Magnolia grandiflora L. (Syst. Nat. ed. 10. 1082. 1759), not

Magnolia foetida (L.) Sargent (Gard. & For. 2: 615. 1889). — Lythrum intermedium Ledeb.
(Ind. Hort. Dorpat 1822) when treated as a variety of Lythrum salicaria L. (1753) must be
called L. salicaria var. glabrum Ledeb. (Fl. Ross. 2: 127. 1843), not L. salicaria var. inter-

medium (Ledeb.) Koehne (Bot. Jahrb. 1: 327. 1881). In all these cases, the name or epithet
given to the taxon in its original rank is replaced by the first correct name or epithet given
to it in its new rank.

Recommendation 60A

(1) When a section or a subgenus becomes a genus, or the inverse change occurs, the
original name or epithet should be retained unless it is contrary to this Code.

(2) When an infraspecific taxon becomes a species, or the inverse change occurs, the
original epithet should be retained unless the resulting combination is contrary to this Code.

(3) When an infraspecific taxon is changed in rank within the species, the original epithet
should be retained unless the resulting combination is contrary to this Code.

————————

* Here and elsewhere in the Code the term “infrageneric” refers to all ranks below that
of genus.

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Article 61

When a taxon of a rank higher than genus and not higher than family is changed
in rank, the stem of the name must be retained and only the termination altered
(-inae, -eae, -oideae, -aceae), unless the resulting name is rejected under Arts. 62—72.

Example: The subtribe Drypetinae Pax (1890) (Euphorbiaceae) when raised to the rank
of tribe becomes Drypeteae (Pax) Hurusawa (1954); the subtribe Antidesmatinae Pax (1890)
(Euphorbiaceae) when raised to the rank of subfamily becomes Antidesmatoideae (Pax)
Hurusawa (1954).

Section 6. REJECTION OF NAMES AND EPITHETS

Article 62

A legitimate name or epithet 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.

Examples: This rule was broken by the change of Staphylea to Staphylis, Tamus to Tham-
nos, Thamnus, or Tamnus, Mentha to Minthe, Tillaea to Tillia, Vincetoxicum to Alexitoxicum;
and by the change of Orobanche rapum to O. sarothamnophyta, O. columbariae to O. colum-
barihaerens, O. artemisiae to O. artemisiepiphyta. All these modifications must be rejected.

— Ardisia quinquegona Blume (1825) must not be changed to A. pentagona A. DC. (1834),
although the specific epithet quinquegona is a hybrid word (Latin and Greek) (see Rec.
23B, c). The name Scilla sibirica Andrews (Bot. Repos. 5: pl. 304. 1804) must not be rejected
because the species does not grow in Siberia. — The name Petrosimonia oppositifolia (Pall.)
Zitw., based on Polycnemum oppositifolium Pall. (Reise 1: 422, 431, app. 484. 1771), must not
be rejected because the species has leaves only partly opposite, and partly alternate, although
there is another closely related species, Petrosimonia brachiata (Pall.) Bunge, having all its
leaves opposite.

Article 63

A name is illegitimate and must be rejected if it was nomenclaturally superfluous
when published, i.e. if the taxon to which it was applied, as circumscribed by its
author, included the type of a name or epithet which ought to have been adopted
under the rules.

Examples: The generic name Cainito Adans. (Fam. 2: 166. 1763) is illegitimate because
it was a superfluous name for Chrysophyllum L. (Sp. Pl. 192. 1753); the two genera had

precisely the same circumscription. — Chrysophyllum sericeum Salisb. (Prodr. 138. 1796) is
illegitimate, being a superfluous name for C. cainito L. (1753), which Salisbury cited as a

synonym. — Picea excelsa (Lam.) Link is illegitimate, because it is based on Pinus excelsus
Lam. (Fl. Franç. 2: 202. 1778), a superfluous name for Pinus abies L. (Sp. Pl. 1002. 1753).

Under Picea the proper name is Picea abies (L.) Karst. (Deutschl. Fl. 325. 1880). — On the
other hand, Cucubalus latifolius Mill. and C. angustifolius Mill. (Gard. Dict. ed. 8. nos. 2., 3.
1768) are not illegitimate names, although these species are now reunited with C. behen L.
(1753), from which Miller separated them: C. latifolius Mill. and C. angustifolius Mill. as
circumscribed by Miller did not include the type of C. behen L.

Note. A nomenclaturally superfluous new combination is not illegitimate if the
epithet of its basionym is legitimate. When published it is incorrect, but it may become
correct later.

Example: Chloris radiata (L.) Sw. (Prodr. 26. 1788), based on Agrostis radiata L. (Syst.
Nat. ed. 10. 2: 873. 1759), was nomenclaturally superfluous when published, since Swartz
also cited Andropogon fasciculatum L. (Sp. Pl. 1047. 1753) as a synonym. It is, however,
the correct name in the genus Chloris for Agrostis radiata when Andropogon fasciculatum
is treated as a different species, as was done by Hackel (in DC. Monogr. Phan. 6: 177. 1889).

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Article 64

A name is illegitimate and must be rejected if it is a later homonym, that is, if
it is spelled exactly like a name previously and validly published for a taxon of the
same rank based on a different type. Even if the earlier homonym is illegitimate, or
is generally treated as a synonym on taxonomic grounds, the later homonym must
be rejected.

Note. Mere orthographic variants of the same name are treated as homonyms
when they are based on different types (see Arts. 73 and 75).

Examples: The name Tapeinanthus Boiss. ex Benth. (1848), given to a genus of Labiatae,
is a later homonym of Tapeinanthus Herb. (1837), a name previously and validly published
for a genus of Amaryllidaceae; Tapeinanthus Boiss. ex Benth. must therefore be rejected,

as was done by Th. Durand (Ind. Gen. Phan. x. 1888), who renamed it Thuspeinanta. — The
generic name Amblyanthera Müll. Arg. (1860) is a later homonym of the validly published
generic name Amblyanthera Blume (1849) and must therefore be rejected, although Am-

blyanthera Blume is now reduced to Osbeckia L. (1753). — Astragalus rhizanthus Boiss.
(Diagn. Pl. Orient. 2: 83. 1843) is a later homonym of the validly published name Astragalus
rhizanthus Royle (Ill. Bot. Himal. 200. 1835) and it must therefore be rejected, as was done
by Boissier, who renamed it A. cariensis (Diagn. Pl. Orient. 9: 56. 1849).

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 infraspecific taxa within
different species.

Examples: Under Verbascum the sectional epithets Aulacosperma and Bothrosperma are
allowed, although there are also in the genus Celsia two sections named Aulacospermae and
Bothrospermae. These, however, are not examples to be followed, since they are contrary
to Rec. 21B.

The following is illegitimate: Erysimum hieraciifolium subsp. strictum var. longisiliquum
and E. hieraciifolium subsp. pannonicum var. longisiliquum — a form of nomenclature which
allows two varieties bearing the same epithet in the same species.

The name Andropogon sorghum subsp. halepensis (L.) Hackel var. halepensis is legitimate,
since the subspecies and the variety have the same type and the epithet must be repeated
under Art. 26.

When the same new name is simultaneously published for more than one taxon,
the first author who adopts it in one sense, rejecting the other, or provides another
name for one of these taxa must be followed.

Example: Linnaeus (Sp. Pl. 1753) published Aira 1 spicata on p. 63 and Aira 7 spicata
on p. 64, but in “Errata” line 9 from base (vol. 2, after “Nomina trivialia” and “Addenda”)
substituted indica for spicata of species 1 on p. 63; the name Aira spicata L. is therefore
legitimate for species 7 on p. 64.

Article 65

A name is illegitimate and must be rejected if it is the name of a taxon which on
transfer of that taxon from the animal to the plant kingdom becomes, at the time
of such transfer, a homonym of a name for a plant taxon.

If a taxon is transferred from the plant kingdom to the animal kingdom, its name
or names retain their status in botanical nomenclature for purposes of homonymy.
In all other cases, the name of a plant must not be rejected merely because it is the
name of an animal.

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Article 66

An epithet of a subdivision of a genus is illegitimate and must be rejected in the
following special cases:

(1) If it was published in contravention of Arts. 51, 54, 57, 58, or 60, i.e. if its
author did not adopt the earliest legitimate epithet available for the taxon with its
particular circumscription, position, and rank.

(2) If it is an epithet of a type subgenus or section which contravenes Art. 22.

Note 1. Illegitimate epithets must not be taken into consideration for purposes of
priority (see Art. 45) except in the rejection of a later homonym (Art. 64).

Note 2. An epithet originally published as part of an illegitimate name may be
made legitimate later in another combination (see Art. 72).

Article 67

A specific or infraspecific epithet is illegitimate and must be rejected if it was
published in contravention of Arts. 51, 53, 55, 56, 57, 58, or 60, i.e. if its author
did not adopt the earliest legitimate epithet available for the taxon with its particular
circumscription, position, and rank.

Note. The publication of a name containing an illegitimate epithet must not be
taken into consideration for purposes of priority (see Art. 45) except in the rejection
of a later homonym (Art. 64).

Article 68

A specific epithet is not illegitimate merely because it was originally published
under an illegitimate generic name, but must be taken into consideration for purposes
of priority if the epithet and the corresponding combination are in other respects
in accordance with the rules. In the same way an infraspecific epithet may be
legitimate even if originally published under an illegitimate name of a species or
infraspecific taxon.

Note. An illegitimate epithet may be made legitimate later in another combination
(see Art. 72).

Article 69

A name must be rejected if it is used in different senses and so has become a long-
persistent source of error.

Examples: The name Rosa villosa L. (Sp. Pl. 491. 1753) is rejected, because it has been

applied to several different species and has become a source of error. — Lavandula spica L.
(Sp. Pl. 572. 1753) included the two species subsequently known as L. angustifolia Mill. and
L. latifolia Vill. The name Lavandula spica has been applied almost equally to these two
species, and, being now ambiguous, must be rejected (see Kew Bull. 1932: 295).

Article 70

A name must be rejected if it is based on a type consisting of two or more entirely
discordant elements, unless it is possible to select one of these elements as a satis-
factory type.

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Examples: The characters of the genus Schrebera L. (Sp. Pl. ed. 2. 1662. 1763; Gen. Pl.
ed. 6. 124. 1764) were derived from the two genera Cuscuta and Myrica (parasite and host)
(see Retz. Obs. 6: 15. 1791). — The characters of the genus Actinotinus Oliv. (Hook. Ic. Pl.
pl. 1740. 1888) were derived from the two genera Viburnum and Aesculus, owing to the
insertion of the inflorescence of a Viburnum in the terminal bud of an Aesculus by a collector.
The names Schrebera L. and Actinotinus Oliv. must therefore be abandoned.

The name of the genus Pouteria Aubl. (Pl. Guiane 85. 1775) is based on a type which is
a mixture of a species of Sloanea (Elaeocarpaceae) and a sapotaceous species (flowers and
leaves); both elements can be easily separated, as has been done by Martius, and Radlkofer
was right in proposing (Sitzber. Math.-Phys. Cl. Bayer. Akad. München 12: 333. 1882) to
retain the name Pouteria as correct for the part of the type belonging to the Sapotaceae.

Article 71

A name must be rejected if it is based on a monstrosity.

Examples: The generic name Uropedium Lindl. (Orch. Linden. 28. 1846) was based on a
monstrosity which is now referred to Phragmipedium caudatum (Lindl.) Rolfe (Orchid Rev. 4:

330. 1896); it must therefore be rejected. — The name Ornithogalum fragiferum Vill. (Hist.
Pl. Dauph. 2: 270. 1787) was based on a monstrosity and must therefore be rejected.

Article 72

In cases foreseen in Arts. 63—71, the name or epithet to be rejected is replaced
by the oldest legitimate name or (in a combination) by the oldest available legitimate
epithet in the rank concerned. If none exists, a new name or epithet must be chosen.
Similar action is to be taken when use of an epithet is inadmissible under Arts. 21,
23, and 24.

Example: Linum radiola L. (1753) when transferred to the genus Radiola must not be
called Radiola radiola (L.) H. Karst. (1882), as that combination is inadmissible under Art. 23;
the next oldest specific epithet is multiflorum, but the name Linum multiflorum Lam. (1778)
is illegitimate, since it was a superfluous name for L. radiola L.: under Radiola, the species
must be called R. linoides Roth (1788), since linoides is the oldest legitimate specific epithet
available.

Note. When a new epithet is required, an author may, if he wishes, 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 epithet in the resultant com-
bination is treated as new.

Example: The name Talinum polyandrum Hook. (Bot. Mag. pl. 4833. 1855) is illegitimate,
being a later homonym of T. polyandrum Ruiz & Pav. (Syst. 1: 115. 1798); when Bentham
transferred T. polyandrum Hook. to Calandrinia, he called it Calandrinia polyandra (Fl.
Austr. 1: 172. 1863). The epithet polyandra in this combination is treated as new, dating from
1863, and the binomial should be written Calandrinia polyandra Benth., not C. polyandra
(Hook.) Benth.

Recommendation 72A

Authors should avoid adoption of an illegitimate epithet previously published for the
same taxon.

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Chapter VI. ORTHOGRAPHY AND GENDER OF NAMES

Section 1. ORTHOGRAPHY OF NAMES AND EPITHETS

Article 73

The original spelling of a name or epithet must be retained, except for the correc-
tion of typographic or orthographic errors.

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

Diacritic signs are not used in Latin plant names. In names (either new or old)
drawn from words in which such signs appear, the signs must 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; ø becomes oe; å becomes
ao; the diaeresis, however, is permissible (Cephaëlis for Cephaelis).*

Note 1. 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, Rec. 73F).

Note 2. The use of a wrong connecting vowel or vowels (or the omission of a
connecting vowel) in a name or an epithet is treated as an orthographic error (see
Rec. 73G).

Note 3. The wrong use of the terminations i, ii, ae, iae, anus, or ianus, mentioned
in Rec. 73C (a, b, d), is treated as an orthographic error.

Note 4. The liberty of correcting a name must be used with reserve, especially
if the change affects the first syllable and, above all, the first letter of the name.

Note 5. When changes made in orthography by earlier authors who adopt
personal, geographic, or vernacular names in nomenclature are intentional latiniza-
tions, they must be preserved.

Note 6. The letters j and v must be changed to i and u respectively when they
represent vowels; the reverse changes must be made when consonants are required.

Examples of retention of original spelling: The generic names Mesembryanthemum L.
(1753) and Amaranthus L. (1753) were deliberately so spelled by Linnaeus and the spelling
must not be altered to Mesembrianthemum and Amarantus respectively, although these latter
forms are philologically preferable (see Kew Bull. 1928: 113, 287). — Valantia L. (1753) and
Clutia L. (1753), commemorating Vaillant and Cluyt respectively, must not be altered
to Vaillantia and Cluytia**: Linnaeus latinized the names of these botanists deliberately as
“Valantius” and “Clutius”. — Phoradendron Nutt. must not be altered to Phoradendrum. —
Triaspis mozambica Adr. Juss. must not be altered to T. mossambica, as in Engler, Pfl.
Ost-Afr. C: 232 (1895). — Alyxia ceylanica Wight must not be altered to A. zeylanica, as in
Trimen, Handb. Fl. Ceyl. 3: 127 (1895). — Fagus sylvatica L. must not be altered to F.

————————

* The diaeresis should be used where required in works in which diphthongs are not
represented by special type, e.g. Cephaëlis in works in which there is Arisaema, not Arisæma.

** In some cases an altered spelling of a generic name is conserved e.g. Bougainvillea
(see list of nomina conservanda no. 2350).

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silvatica. The correct classical spelling silvatica is recommended for adoption in the case of
a new name (Rec. 73E), but the mediaeval spelling sylvatica, deliberately adopted by Lin-

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

Examples of typographic errors: Globba brachycarpa Baker (in Hook. f. Fl. Brit. Ind. 6:
205. 1890) and Hetaeria alba Ridley (Journ. Linn. Soc. Bot. 32: 404. 1896) are typographic
errors for Globba trachycarpa Baker and Hetaeria alta Ridley respectively (see Journ. of Bot.
59: 349. 1921). — Thevetia nereifolia Adr. Juss. ex Steud, is an obvious typographic error
for T. neriifolia.

Examples of orthographic errors: — Hexagona Fr. (Epicr. 496. 1836-38) was an orthographic
error for Hexagonia; Fries had previously (Syst. Myc. 1: 344. 1821) cited Hexagonia Poll.
erroneously as “Hexagona Poll.”. — Gluta benghas L. (Mant. 293.1771), being an orthographic
error for G. renghas, should be cited as G. renghas L., as has been done by Engler (in DC.
Monogr. Phan. 4: 22.5. 1883); the vernacular name used as a specific epithet by Linnaeus is
“Renghas”, not “Benghas”. — Pereskia opuntiaeflora DC. (Mém. Mus. Hist. Nat. Paris 17: 76.
1828) should be cited as P. opuntiiflora DC. (cf. Rec. 73G). — Cacalia napeaefolia DC.
(in DC. Prodr. 6: 328. 1837) and Senecio napeaefolius (DC.) Schultz-Bip. (Flora 28: 498. 1845)
should 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 reduced stem-ending i should have been used instead of ae. —
Dioscorea lecardi De Wild. should be corrected to D. lecardii, and Berberis wilsonae Hemsl.
should be corrected to B. wilsoniae: the genitive forms derived from Lecard (m) and Wilson
(f) prescribed by Rec. 73C are lecardii and wilsoniae respectively.

Example of both a typographic and an orthographic error: Rosa pissarti Carr. (Rev. Hort.
1880: 314) is a typographic error for R. pissardi (see Rev. Hort. 1881: 190), which may be
corrected to R. pissardii (see Rec. 73C, b).

Examples illustrating Note 6: Taraxacvm Zinn must be changed to Taraxacum, Iungia L. f.
to Jungia, Saurauja Willd. to Saurauia.

Recommendation 73A

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

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

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

Recommendation 73B

When a new name for a genus, subgenus, or section is taken from the name of a person,
it should be formed in the following manner:

(a) When the name of the person ends in a vowel, the letter a is added (thus Bouteloua
after Boutelou; Ottoa after Otto; Sloanea after Sloane), except when the name ends in a,
when ea is added (e.g. Collaea after Colla).

(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).

(c) The syllables not modified by these endings retain their original spelling, unless they
contain letters foreign to Latin plant names or diacritic signs (see Art. 73).

(d) 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.

Examples: Durvillea and Urvillea; Lapeirousia and Peyrousea; Englera, Englerastrum, and
Englerella; Bouchea and Ubochea; Gerardia and Graderia; Martia and Martiusia.

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Recommendation 73C

When a new specific or infraspecific epithet is taken from the name of a man, it should
be formed in the following manner:

(a) When the name of the person ends in a vowel, the letter i is added (thus glazioui
from Glaziou, bureaui from Bureau), except when the name ends in a, when e is added
(thus balansae from Balansa).

(b) When the name ends in a consonant, the letters ii are added (ramondii from Ramond),
except when the name ends in -er, when i is added (thus kerneri from Kerner).

(c) The syllables not modified by these endings retain their original spelling, unless they
contain letters foreign to Latin plant names or diacritic signs (see Art. 73).

(d) When epithets taken from the name of a man have an adjectival form they are
formed in a similar way (e.g. Geranium robertianum, Verbena hasslerana, Asarum hayatanum).

(e) If the personal name is already Latin or Greek, the appropriate Latin genitive should be
used, e.g. alexandri from Alexander, francisci from Franciscus, augusti from Augustus, linnaei
from Linnaeus, hectoris from Hector.

The same provisions apply to epithets formed from the names of women. When these have
a substantival form, they are given a feminine termination (e.g. Cypripedium hookerae, Rosa
beatricis, Scabiosa olgae, Omphalodes luciliae).

Recommendation 73D

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

Examples: Rubus quebecensis (from Quebec), Ostrya virginiana (from Virginia), Polygonum
pensylvanicum (from Pennsylvania).

Recommendation 73E

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).

Examples: silvestris (not sylvestris), sinensis (not chinensis).

Recommendation 73F

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

A compound name or an epithet combining elements derived from two or more Greek
or Latin words should be formed, as far as practicable, in accordance with classical usage
(see Note 2 to Art. 73). This may be stated as follows:

(a) In a true compound (as distinct from pseudocompounds such as Myos-otis, nidis-avis)
a noun or adjective in a non-final position appears as a bare stem without case-ending (Hydro-
phyllum).

(b) Before a vowel the final vowel of this stem, if any, is normally elided (Chrys-anthemum,
mult-angulus), with the exception of Greek y and i (poly-anthus, Meli-osma).

(c) Before a consonant the final vowel is normally preserved in Greek (mono-carpus, Poly-
gonum, Coryne-phorus, Meli-lotus), except that a is commonly replaced by o (Hemero-callis
from hemera); in Latin the final vowel is reduced to i (multi-color, menthi-folius, salvii-folius).

(d) If the stem ends in a consonant, a connecting vowel (o in Greek, i in Latin) is inserted
before a following consonant (Odont-o-glossum, cruc-i-formis).

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Some irregular forms, however, have been extensively used through false analogy (atro-
purpureus, on the analogy of pseudo-compounds such as fusco-venatus in which o is the
ablative case-ending). Others are used as revealing etymological distinctions (caricae-formis
from Carica, as distinct from carici-formis from Carex). Where such irregularities occur in
the original spelling of existing compounds, this spelling should be retained.

Note. The hyphens in the above examples are given solely for explanatory reasons. They
should all be eliminated in botanical names and epithets except in nidis-avis, terrae-novae
and similar Latin pseudo-compounds.

Recommendation 73H

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 must be
regarded as orthographic variants and should be corrected.

Examples: Phyllachora anonicola Chardon, 1940, should be altered to P. annonicola, since
the spelling Annona is now accepted in preference to Anona; Meliola albizziae Hansford et
Deighton, 1948, should be altered to M. albiziae, since the spelling Albizia is now accepted
in preference to Albizzia.

Article 74

When the spelling of a generic name differs in Linnaeus’ Species Plantarum ed. 1
and Genera Plantarum ed. 5, the correct spelling is determined by the following
regulations:

(1) If Linnaeus subsequently to 1753-54 consistently adopted one of the spellings,
that spelling is accepted, e.g. Thuja (not Thuya), Prunella (not Brunella).

(2) If Linnaeus did not do so, then the spelling which is more correct philo-
logically is accepted, e.g. Agrostemma (not Agrostema), Euonymus (not Evonymus).

(3) If the two spellings are equally correct philologically, and there is a great
preponderance of usage in favour of one of them, that one is accepted, e.g. Rhodo-
dendron (not Rhododendrum).

(4) If the two spellings are equally correct philologically, and there is not a great
preponderance of usage in favour of one of them, then the spelling that is in
accordance or more nearly in accordance with Recommendations 73A, 73B, and 73G
is accepted, e.g. Ludwigia (not Ludvigia), Ortegia (not Ortega).

Article 75

When two or more generic names 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 variants, which are homonyms when they are based on different types.

Examples of names treated as orthographic variants: Astrostemma and Asterostemma;
Pleuripetalum and Pleuropetalum; Collumella and Columellia, both commemorating Columella,
the Roman writer on agriculture; Eschweilera and Eschweileria; Skytanthus and Scytanthus.

— The three generic names Bradlea Adans., Bradleja Banks ex Gaertn., and Braddleya Veil., all
commemorating Richard Bradley (1675-1732), must be treated as orthographic variants because
one only can be used without serious risk of confusion.

Examples of names not likely to be confused: Rubia and Rubus; Monochaete and
Monochaetum; Peponia and Peponium; Iria and Iris; Desmostachys and Desmostachya;
Symphyostemon and Symphostemon; Gerrardina and Gerardiina; Durvillea and Urvillea;
Elodes and Elodea; Peltophorus (Poaceae) and Peltophorum (Fabaceae).

————————

* When it is doubtful whether names are sufficiently alike to be confused, they should
be referred to the General Committee.

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The same applies to specific epithets within the same genus and to infraspecific
epithets within the same species.

Examples of epithets treated as orthographic variants: 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; trachy-
caulum and trachycaulon.

Examples of epithets not likely to be confused: Senecio napaeifolius (DC.) Schultz-Bip.
and S. napifolius Macowan are different names, the epithets napaeifolius and napifolius being
derived respectively from Napaea and Napus. — Lysimachia hemsleyana and Lysimachia
hemsleyi (see, however, Rec. 23A).

Section 2. GENDER OF GENERIC NAMES

Recommendation 75A

The gender of generic names should be determined as follows:

(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, whose classical gender is
masculine, should be treated as feminine in accordance with botanical custom: Adonis,
Diospyros, Strychnos; so also should Orchis and Stachys, which are masculine in Greek and
feminine in Latin. The name Hemerocallis, derived from the Latin and Greek hemerocalles
(n.), although masculine in Linnaeus’ Species Plantarum, should be treated as feminine in
order to bring it into conformity with all other generic names ending in -is.

(2) Generic names formed from two or more Greek or Latin words should take the gender
of the last. If the ending is altered, however, the gender should follow it.

Examples of names formed from Greek words:*

Modern compounds ending in -codon, -myces, -odon, -panax, -pogon, -stemon, and other
masculine words should be masculine. The fact that the generic name Andropogon L. was
originally treated as neuter by Linnaeus is immaterial.

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. The fact that Dendromecon Benth. and Hesperomecon E. L. Greene were
originally ascribed the neuter gender is immaterial. 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.

Similarly, all modern compounds ending in -ceras, -dendron, -nema, -stigma, -stoma, and
other neuter words should be neuter. The fact that Robert Brown and Bunge respectively
made Aceras and Xanthoceras feminine is immaterial. 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.

Examples of 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.

————————

* Examples of names formed from Latin words are not given as these offer few difficulties.

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(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.

Examples: Taonabo Aubl. (Pl. Guiane 569. 1775) should be feminine: Aublet’s two species
were T. dentata and T. punctata. — Agati Adans. (Fam. 2: 326. 1763) was published without
indication of gender: the feminine gender was assigned to it by Desvaux (Journ. de Bot. 1:
120. 1813), who was the first subsequent author to adopt the name, and his choice should be
accepted. — Boehmer (in Ludwig, Def. Gen. Pl. ed. 3. 436. 1760) and Adanson (Fam. 2:
356. 1763) failed to indicate the gender of Manihot: the first author to supply specific
epithets was Crantz (Inst. Rei Herh. 1: 167. 1766), who proposed the names Manihot gossypii-
folia, etc., and Manihot should therefore be treated as feminine. — Cordyceps Link (Handb.
3: 346. 1833) is adjectival in form and has no classical gender; Link assigned to it C. capitatus,
etc., and Cordyceps should therefore be treated as masculine.

(4) Generic names ending in -oides or -odes should be treated as feminine irrespective
of the gender assigned to them by the original author.

Recommendation 75B

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.

Example: When Boletus is divìded, the gender of the new generic names should be
masculine: Xerocomus, Boletellus, etc.

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Division I I I . Provisions for modification of the Code

Provision 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.

Provision 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 Botanical Congress.
The Committees have power to co-opt and to establish subcommittees; such officers
as may be desired are elected.

      1. General Comittee, 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
Congress.
      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 Bacteria.
      8. Committee for Virus.
      9. Committee for Cultivated Plants.
    10. Committee for Fossil Plants.
    11. Editorial Committee, charged with the preparation and publication of the Code in
conformity with the decisions adopted by the International Botanical Congress. Chairman: the
rapporteur-général of the previous Congress, who is charged with the general duties in
connection with the editing of the Code.

Provision 3. The Bureau of Nomenclature of the International Botanical Congress.

Its officers are: 1. The president of the Nomenclature Section, elected by 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.

Provision 4. The voting on nomenclature proposals is of two kinds: 1. a pre-
liminary guiding mail vote and 2. a final and binding vote at the Nomenclature
Section of the International 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. No accumulation or transfer of personal votes is permissible.

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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.

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Appendix I

Names of hybrids and some special categories

Article H. 1

Hybrids or putative hybrids between two species of the same genus are designated
by a formula and, whenever it seems useful or necessary, by a name.

The formula consists of the names of the two parents connected by the multiplication
sign (× ) or the name of the genus followed by the specific epithets of the two
parents connected by the same sign. When the hybrid is of known experimental
origin, the formula may be made more precise by the addition of the sign ♀ to the
epithet of the parent producing the female gamete and ♂ to the epithet of the parent
producing the male gamete.

The name, which is subject to the same rules as names of species, is distinguished
from the latter by the multiplication-sign × before the (“specific”) epithet.

Where binary “specific” names of Latin form are used for hybrids, all offspring
of crosses between individuals of the same parent species receive the same binary
name. An exception may be made for names of amphidiploids treated as species,
which may bear a separate epithet without the multiplication sign (× ) and are then
subject to the same rules as names of species.

Examples: Digitalis lutea ♀ × D. purpurea ♂ — Salix × capreola = Salix aurita × S.
caprea, or alternatively Salix aurita × caprea.

Note 1. When polymorphic parental species are involved and if infraspecific taxa
are recognized in them, greater precision may be achieved by the use of formulae
than by giving the hybrids “specific” names.

Note 2. Designations consisting of the specific epithets of the parents combined
in unaltered form by a hyphen, or with the ending of only one epithet changed, or
consisting of the specific epithet of one parent combined with the generic name of
the other (with or without change of ending) are considered as formulae and not
as true epithets.

Examples: The designation Potentilla atrosanguinea-formosa published by Maund is con-
sidered as a formula meaning Potentilla atrosanguinea × P. formosa. — Verbascum nigro-
lychnitis Schiede (Pl. Hybr. 40. 1825) is considered as a formula, Verbascum lychnites × V.
nigrum; the correct binary name for this hybrid is Verbascum × schiedeanum Koch.

Note 3. Graft chimaeras (sometimes called “graft hybrids”), being horticultural
objects, are dealt with by the International Code of Nomenclature for Cultivated
Plants.

Note 4. The order of the names or epithets in the formula may be either alpha-
betical (as in this Code) or with the name or epithet of the female parent first when
this is known. The female (♀ ) and male ( ♂ ) signs may be added if desired. The
method used in any publication should be clearly stated.

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Article H. 2

Hybrids or putative hybrids between infraspecific taxa of the same species may
be designated by a formula and, whenever it seems useful or necessary, by a name
of the same taxonomic rank as the parents or, if these are of different rank, that
of the higher-ranking parent. In the formula the order of the names or epithets
and the use of the signs ♀ and ♂ should follow the procedure set down in Art. H. 1.

Note. In general greater precision will be achieved with less danger of confusion
if formulae rather than names are used for such hybrids.

Example: Lilium davidii var. davimottiae (= L. davidii var. davidii × L. davidii var.
willmottiae).

Article H. 3

Bigeneric hybrids (i.e. hybrids between species of two genera) are designated by
a formula and, whenever it seems useful or necessary, by a name.

The formula consists of the names of the two parents connected by the multi-
plication-sign ×.

The name consists of a new “generic” name usually formed by an euphonious
combination of parts of the names of the two parent genera, and a (“specific”)
epithet.

The epithet of a bigeneric hybrid must not be placed under the name of either
of the parent genera.

All hybrids between the same two genera bear the same “generic” name, this to
be preceded by the multiplication-sign ×.

Examples: × Asplenophyllitis (= Asplenium × Phyllitis); × Heucherella (= Heuchera ×
Tiarella); × Heucherella tiarelloides (= Heuchera × brizoides × Tiarella cordifolia), not
Heuchera × tiarelloides; × Mahoberberis (= Berberis × Mahonia).

Note. “Hybrid subgenera” and “hybrid sections” may be named in the same way.

Example: Iris subgen. × Regeliocyclus, comprising the hybrids between species belonging
to subgenus Regelia and subgenus Oncocyclus.

Article H. 4

Ternary hybrids, or those of a higher order, are designated like ordinary hybrids
by a formula and, whenever it seems useful or necessary, by a binary name. Such
as are trigeneric or multigeneric may be given new generic names formed by a
combination of parts of the names of the parent genera; usually, however, multi-
generic hybrid groups combining three or more genera receive a conventional name
consisting of the name of a person eminent as a collector, grower, or student of the
group, to which is added the termination -ara; no such name may exceed eight syllables.

Examples: Salix × straehleri [= Salix aurita × S. cinerea × S. repens or, alternatively,
Salix (aurita × repens) × S. cinerea].

× Sanderara (= Brassia × Cochlioda × Odontoglossum); × Potinara (= Brassavola ×
Cattleya × Laelia × Sophronitis). Correct validly published compounds such as × Dialaelio-
cattleya (composed of the generic name Cattleya, and parts of Diacrium and Laelia) must,
however, be retained.

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Article H. 5

When different hybrid forms of the same parentage (pleomorphic hybrids, com-
binations between different forms of a collective species, segregates, back-crosses)
are united in a collective taxon, the subdivisions are classed under the binary name
applied to the hybrid population or group like the subdivisions of a species under
the binary name of the species. These forms are recognized as nothomorphs; when
desirable a nothomorph may be designated by an epithet preceded by the binary
name of the hybrid group and the term “nothomorph” (nothomorpha, abbreviated
as nm.).

Note. Nothomorpha: — a term derived from the Greek νοθος and μορφη
meaning “hybrid form” and applied to any hybrid form, whether Fı, segregate,
or backcross.

Examples: Mentha × niliaca nm. lamarckii (a form of the pleomorphic hybrid Mentha ×
niliaca = M. longifolia × M. rotundifolia); Ulmus × hollandica nm. hollandica and nm.
vegeta (forms of Ulmus × hollandica = U. carpinifolia × U. glabra).

Recommendation H. 5A

Taxa which are apomicts may, if desired, be designated as such in the following manner:

(1) If they are considered of specific rank, by the interpolation of the abbreviation “ap.”
between the generic name and the epithet.

(2) If they are considered as of infraspecific rank, by the interpolation of the abbreviation
“ap.” between the term denoting the rank and the infraspecific epithet.

Taxa which are clones may, if desired, be designated as such by the use of the term
“clone” (abbreviated as “cl.”) in the same manner as “ap.”.

Appendix II

Nomina familiarum conservanda

see pp. 187-201

Appendix III

Nomina generica conservanda et rejicienda

see pp. 202-338

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GUIDE FOR THE DETERMINATION OF TYPES

The following is intended as a guide to the determination or selection of the
nomenclatural types of previously published taxa. Where the application of a rule
is concerned, reference is made to the appropriate Article.

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.

2. A new name or epithet published as an avowed substitute (nomen novum)
for an older name or epithet is typified by the type of the older name (Art. 7,
Note 4).

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, Note 3).

4. Designation of a lectotype should be undertaken only in the light of an
understanding of the group concerned. Mechanical systems, 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. In choosing a lectotype,
all aspects of the protologue* should be considered as a basic guide.

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 and included in
the protologue.

b. Other things being equal, a specimen should be given preference over pre-
Linnaean or other cited descriptions or illustrations when lectotypes of species or
infraspecific taxa are designated.

c. If a holotype was designated by the original author and has been lost or
destroyed, an isotype (Art. 7, Note 3), if such exists, must be chosen as the
lectotype. If no holotype was designated by the original author and if syntypes
(Art. 7, Note 3) exist, one of them must be chosen as tbe lectotype. If no holotype
was designated by the original author and if no syntypes are extant, the lectotype
should be chosen from among duplicates** of the syntypes (isosyntypes), if such

————————

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

** 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 corres-
ponding caution used.

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exist. If neither an isotype, a syntype, nor an isosyntype is extant, a paratype***, if
such exists, may be chosen as lectotype. If none of the specimens cited in the proto-
logue nor any duplicates of them are extant, a neotype (Art. 7, Note 3) may be
designated.

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 protologue.
Such indications are manuscript notes, annotations on herbarium sheets, recognizable
figures, and epithets such as typicus, genuinus, vulgaris, communis, etc.

e. In cases when two or more elements were included in or cited with the original
description, the reviewer should use his best judgment in the selection of a lecto-
type, but if another author has already segregated one or two elements as other
taxa, the residue or part of it should be designated as the lectotype if its essential
characters correspond with the original description. If it can be shown that the
element best fitting the protologue has been removed, it should be restored and
treated as the lectotype. Whenever the original material of a taxon is heterogeneous,
the lectotype should be selected so as to preserve current usage unless another
element agrees better with the protologue (Rec. 7B).

f. The first choice of a lectotype must be followed by subsequent workers (Art. 8)
unless the original material is rediscovered, or unless it can be shown that the choice
was based upon a misinterpretation of the protologue.

5. In selecting a neotype even more 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. A neotype may be designated only when all the originally cited material
and its duplicates are believed lost or destroyed (Art. 7, Note 3).

The first choice of a neotype must be followed by subsequent workers unless the
original material is rediscovered, or unless the choice neglected an available lecto-
type, or if it can be shown that the choice was based on a misinterpretation of the
original protologue. A lectotype always takes precedence over a neotype (Art. 7,
Note 3).

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 (Rec. 7C).

————————

*** A paratype is a specimen cited in the protologue other than the holotype or isotype(s).
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, Note 3), the remaining cited specimens are paratypes and not
syntypes.

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GUIDE TO THE CITATION OF BOTANICAL NOMENCLATURE

A reference to literature in a botanical publication should consist of the following
items, in the order in which they are treated below:

1. Name of Author(s). In a citation appended to the name of a taxon, the name
of the author should be abbreviated as recommended in Rec. 46A. In other citations
(as in bibliographies), the name of the author should be given in full; the last name
first, followed by first name(s). The use of the full name (rather than initials)
tends to avoid errors.

If several authors are cited, the name of the last should be preceded by the
word et or by the sign “&” (see Rec. 46B).

After the name of a taxon, an unabbreviated author’s name should be separated
from what follows by a comma; an abbreviated name needs no punctuation other
than the period (full stop) indicating abbreviation.

2. Title. After the name of a taxon, the title of a book is commonly abbreviated,
and the title of an article in a serial is commonly omitted. Elsewhere (as in biblio-
graphies), titles should be cited exactly as they appear on the title-page of the book
or at the head of the article.

In a citation appended to the name of a taxon, no punctuation should separate
the title from what follows other than a period (full stop) indicating abbreviation.

Examples of Taxonomic Citation of Authors and Titles: P. Br. Hist. Jam. — Hook. f. Fl.
Brit. Ind. — G. F. Hoffm. Gen. Umbell. — G. Don, Gen. Hist. — H.B.K. Nov. Gen. Sp. —
L. Sp. Pl. — Michx. Fl. Bor.-Am. — DC. Prodr. — T. et G. Fl. N. Am. The last five authors’
names are not abbreviated strictly in accordance with Rec. 46A. but with common usage.

Examples of Names written in full: Mueller, Ferdinand Jacob Heinrich von. — Müller,
Johann Friedrich Theodor (“Fritz Müller”). — Mueller, Ferdinand Ferdinandowitsch. —
Müller, Franz August. Müller, Franz.

3. Name of Serial. Principal words should be abbreviated* to the first syllable,
with such additional letters or syllables as may be necessary to avoid confusion;
articles, prepositions, and other particles (der, the, of, de, et, and so forth) should
be omitted except when that omission might create confusion. The order of words
should be that which appears on the title-page. Unnecessary words, subtitles, and
the like should be omitted.

To avoid confusion among publications having the same name or very similar
names, the place of publication or other distinguishing data should be added in
brackets.

No punctuation other than a period (full stop) indicating abbreviation should
separate the name of the serial from what follows.

Examples of Citation of Names of Serials: Ann. Sci. Nat.; not Ann. des Sci. Nat. — Am.
Journ. Bot.; not Amer. Jour. Bot. — Bot. Jahrb. (Botanische Jahrbücher für Systematik,
Pflanzengeschichte und Pflanzengeographie); not Engl. Bot. Jahrb. (Engler was the editor,

————————

* Titles consisting of a single word, and personal names, are customarily not abbreviated;
but many exceptions are sanctioned by usage.

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not the author of the series). — Mem. Soc. Cub. Hist. Nat. (Memorias de la Sociedad
Cubana de Historia Natural “Felipe Poey”). — Acta Soc. Faun. Fl. Fenn. (Acta Societatis
pro Fauna et Flora Fennica). — Bull. Jard. Bot. Etat [Bruxelles] (Bulletin du Jardin
Botanique de l’État). — Flora [Quito] (to distinguish it from the well-known “Flora”
published in Jena). — Hedwigia; not Hedwig. — Gartenflora; not Gartenfl. — Missouri Bot.
Gard. Bull.; not Bull. Mo. Bot. Gard. (see title-page).

4. Edition and Series. If a book has appeared in more than one edition, those
subsequent to the first should be designated by “ed. 2”, “ed. 3”, and so forth.

If a serial has appeared in more than one series in which the numbers of volumes
are repeated, those subsequent to the first should be designated by a roman capital
numeral, or by “ser. 2”, “ser. 3”, and so forth.

Examples of Editions and Series: G. F. Hoffm. Gen. Umbell. ed. 2. — Compt. Rend.
Acad. URSS. II. (Comptes Rendus de l’Académie des Sciences de l’URSS. Nouvelle Série).
— Ann. Sci. Nat. IV. — Mem. Am. Acad. II. (or ser. 2.) (Memoirs of the American Academy
of Arts and Sciences. New Series); not Mem. Am. Acad. N.S.

5. Volume. The volume should be shown by an arabic numeral; for greater
clarity this should be printed in boldface type. When volumes are not numbered,
the years on the title-pages may be used as volume-numbers.

The volume-number should always be separated from the numbers of pages and
illustrations by a colon.

6. Part or Issue. If a volume consists of separately paged parts, the number of
the part should be inserted immediately after the volume-number (and before the
colon), either in parentheses or as a superscript. For volumes which are continuously
paged, the designation of parts serves no useful purpose and leads to typographical
errors.

7. Pages. Pages are shown by arabic numerals, except those otherwise designated
in the original. If several pages are cited, the numbers are separated by commas; or
if more than two consecutive pages are cited, the first and last are given, separated
by a dash.

8. Illustrations. Figures and plates, when it is desirable to refer to them, should
be indicated by arabic numerals preceded by f. and pl. or t. (tabula) respectively;
for greater clarity these should be printed in italic type.

9. Dates. The year of publication should end the citation; or, in lists of works to
which reference is made by author and date, it may be inserted between the author’s
name and the title of his work. If it is desirable to cite the exact date, day, month,
and year should be given in that order. The date (in either position) may be
enclosed in parentheses.

Note. With the exceptions above noted, each item of the citation should be
separated from the following item by a period (full stop).

Examples of Citations Appended to Names of Taxa: Anacampseros Sims, Bot. Mag. 33:
pl. 1367. 1811. — Tittmannia Brongn. Ann. Sci. Nat. 8: 385. 1826. — Monachaetum Naud.
Ann. Sci. Nat. III. 4: 48. pl. 2. 1845. — Cudrania Tréc. Ann. Sci. Nat. ser. 3. 8: 122. f. 76-85.

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1847. — Symphyoglossum Turcz. Bull. Soc. Nat. Mosc. 21¹: 255. 1848. — Hedysarum gremiale
Rollins, Rhodora 42: 230 (1940). — Hydrocotyle nixioides Math. & Const. Bull. Torrey Club
78: 303. 24 July 1951. — Ferula tolucensis H.B.K. Nov. Gen. Sp. 5: 12. 1821. — Critamus
dauricus G. F. Hoffm. Gen. Umbell. ed. 2. 184. 1816. — Geranium tracyi Sandw. Kew Bull.
1941: 219. 9 March 1942. — Sanicula tuberosa Torr. Pacif. Railr. Rep. 4(1): 91. 1857.

Examples of Bibliographic Citations: Norton, John Bitting Smith. Notes on some plants,
chiefly from the southern United States. Missouri Bot. Gard. Rep. 9: 151-157. pl. 46-50. 1898.

Reichenbach, Heinrich Gottlieb Ludwig. Handbuch des natürlichen Pflanzensystems. i-x,
1-346. 1837.

Don, George. A general history of the dichlamydeous plants. 1: 1-818 (1831). 2: 1-875
(1832). 3: 1-867 (1834). 4: 1-908 (1838).

Schmidt, Friedrich. Reisen im Arnur-Lande und auf der Insel Sachalin. Botanischer Theil.
Mém. Acad. St.-Pétersb. VII. 12²: 1-277. pl. 1-8. June 1868.

Glover, George Henry & Robbins, Wilfred William. 1915. Colorado plants injurious to
livestock. Bull. Colorado Exp. Sta. 211: 3-74. f. 1-92.

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KEY TO THE NUMBERING OF THE ARTICLES AND RECOMMENDATIONS

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BIBLIOGRAPHIA

LOIS / DE LA / NOMENCLATURE BOTANIQUE / ADOPTÉES PAR / LE
CONGRÈS INTERNATIONAL DE BOTANIQUE / TENU A PARIS EN AOUT 1867
/ SUIVIES D’UNE / DEUXIÈME ÉDITION / DE L’INTRODUCTION HISTO-
RIQUE ET DU COMMENTAIRE / QUI ACCOMPAGNAIENT LA RÉDACTION
PRÉPARATOIRE PRÉSENTÉE AU CONGRÈS / PAR / M. ALPH. DE CANDOLLE
/ Éditeur et en partie auteur du / Prodromus systematis naturalis vegetabilum. /
— / GENÈVE ET BALE / H. GEORG, LIBRAIRE-ÉDITEUR / PARIS / J.-B.
BAILLIÈRE ET FILS / 1867 /

In 8°; p. [1]-64; ‘Lois’: p. 13-32, ‘Commentaire’: p. 33-64. Sometimes referred to as ‘Paris
Code’ or ‘Paris Rules’.

RÈGLES INTERNATIONALES / DE LA / NOMENCLATURE BOTANIQUE /
ADOPTÉES PAR LE / CONGRÈS INTERNATIONAL DE BOTANIQUE DE
VIENNE 1905 / ET PUBLIÉES AU NOM DE LA COMMISSION DE RÉDACTION
DU CONGRÈS / PAR / JOHN BRIQUET / RAPPORTEUR GÉNÉRAL. / INTER-
NATIONAL RULES OF / BOTANICAL NOMENCLATURE / ADOPTED BY THE
INTERNATIONAL BOTANICAL CONGRESS OF VIENNA 1905. / — / INTER-
NATIONALE REGELN DER / BOTANISCHEN NOMENCLATUR / ANGENOMMEN
VOM INTERNATIONALEN BOTANISCHEN KONGRESS ZU WIEN 1905. / — /
VERLAG VON GUSTAV FISCHER IN JENA. / 1906. /

In 8° max.; p. [1]-99; Commission de Rédaction: J. Briquet, Ch. Flahault, H. Harms,
A. B. Rendle. Title on p. 17: ‘Règles internationales pour la Nomenclature botanique prin-
cipalement des plantes vasculaires’. Sometimes referred to as ‘Vienna Code’ or ‘First edition
of the Rules’. Also published in ‘Verhandlungen des internationalen botanischen Kongresses
in Wien 1905’, Jena 1906, pp. 165-261.

RÈGLES INTERNATIONALES / DE LA / NOMENCLATURE BOTANIQUE
/ ADOPTÉES PAR LE / CONGRÈS INTERNATIONAL DE BOTANIQUE DE
VIENNE 1905 / DEUXIÈME ÉDITION MISE AU POINT D’APRÈS LES /
DÉCISIONS DU CONGRÈS INTERNATIONAL DE / BOTANIQUE DE BRUXEL-
LES 1910 / PUBLIÉE AU NOM DE LA COMMISSION DE RÉDACTION DU
CONGRÈS / PAR / JOHN BRIQUET / RAPPORTEUR GÉNÉRAL / — / INTER-
NATIONAL RULES / OF BOTANICAL NOMENCLATURE / ADOPTED BY THE
INTERNATIONAL BOTANICAL CONGRESSES / OF VIENNA 1905 AND
BRUSSELS 1910 / — / INTERNATIONALE REGELN / DER BOTANISCHEN
NOMENCLATUR / ANGENOMMEN VON DEN INTERNATIONALEN BOTA-
NISCHEN KONGRESSEN / ZU WIEN 1905 UND BRÜSSEL 1910 / JENA /
VERLAG VON GUSTAV FISCHER / 1912 /

In 8° max.; p. [I]-VIII, [1]-110; Commission de Rédaction: J. Briquet, H. Harms, L.
Mangin, A. B. Rendle. Title on p. 12 (cf. p. 17, Vienna Code): ‘II. Règles internationales
de la Nomenclature botanique’. Sometimes referred to as ‘Brussels Code’, ‘Brussels Rules’,
‘Second edition of the Rules’.

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INTERNATIONAL RULES / OF / BOTANICAL NOMENCLATURE / ADOPTED
BY THE INTERNATIONAL BOTANICAL CONGRESSES / OF VIENNA, 1905,
AND BRUSSELS, 1910 / REVISED BY THE INTERNATIONAL BOTANICAL
CONGRESS / OF CAMBRIDGE, 1930 / COMPILED BY THE EDITORIAL COM-
MITTEE FOR NOMENCLATURE FROM THE REPORT OF / THE SUBSECTION
OF NOMENCLATURE PREPARED BY / JOHN BRIQUET (†) / — / RÈGLES
INTERNATIONALES / DE LA NOMENCLATURE BOTANIQUE / ADOPTÉES
PAR LES CONGRÈS INTERNATIONAUX DE BOTANIQUE DE VIENNE, 1905,
/ BRUXELLES, 1910, ET CAMBRIDGE, 1930 / — / INTERNATIONALE REGELN
/ DER BOTANISCHEN NOMENCLATUR / ANGENOMMEN VON DEN INTER-
NATIONALEN BOTANISCHEN KONGRESSEN ZU WIEN 1905, / BRÜSSEL 1910
UND CAMBRIDGE 1930 / DRITTE AUSGABE / — / VERLAG VON GUSTAV
FISCHER IN JENA / 1935 /

In 8° max.; p. [I]-[XII], [1]-[152]; General editor: H. Harms; English text (primary)
prepared by A. B. Rendle, in collaboration with J. Ramsbottom, T. A. Sprague and A. J.
Wilmott; French text prepared by B. P. G. Hochreutiner; German text prepared by H. Harms.
An unofficial abridged edition of the English text was issued by A. B. Rendle as a supple-
ment to ‘The Journal of Botany’, June 1934, entitled: ‘International Rules of Botanical
Nomenclature adopted by the Fifth International Botanical Congress, Cambridge, 1930’. The
abridgement consisted merely in the omission of most of the examples and of the Appendices.
Mostly referred to as ‘Cambridge Rules' or ‘Third edition of the Rules’.

International Rules of / Botanical Nomenclature / Formulated by the International
Botanical Congresses of Vienna, 1905, / Brussels, 1910, and Cambridge 1930 /
Adopted and revised by the International Botanical Congress of Amsterdam, 1935
/ Compiled from various sources by / W. H. Camp, H. W. Rickett and C. A.
Weatherby / UNOFFICIAL SPECIAL EDITION / Issued as a service to members
of the / American Society of Plant Taxonomists / Published by / THE NEW YORK
BOTANICAL GARDEN / in co-operation with / THE AMERICAN SOCIETY OF
PLANT TAXONOMISTS / THE SCIENCE PRESS PRINTING COMPANY /
LANCASTER, PENNSYLVANIA /
Top line: / Vol. 6, No. 1, pp. 1—120 BRITTONIA APRIL 9, 1947 /

    In 8°; p. [1]-120; Brittonia 6(1): 1-120. 1947.
    Second printing, 1948, reproduced by offset and published by the Chronica Botanica Co.
Waltham, Mass., U.S.A. for the New York Botanical Garden, and the American Society of
Plant Taxonomists.
    Mostly referred to as ‘Brittonia edition of the Rules’.

INTERNATIONAL RULES / of / BOTANICAL NOMENCLATURE / SUPPLE-
MENT / embodying the alterations made at the / Sixth International Botanical
Congress, Amsterdam, 1935 / compiled by / T. A. SPRAGUE, D. Sc. / late Deputy
Keeper of the Herbarium, Royal Botanic Gardens, Kew / Rapporteur Général for
Nomenclature, Sixth International Botanical Congress / — / (65) /

In 8°: In: Chronica Botanica, Volume 12, Number 1/2, pp. (65)-[88]. 1950.

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INTERNATIONAL CODE / OF / BOTANICAL NOMENCLATURE / ADOPTED
BY / THE SEVENTH INTERNATIONAL BOTANICAL / CONGRESS, STOCK-
HOLM, JULY 1950 PREPARED BY / J. LANJOUW, Chief Editor / CH. BAEHNI,
E. D. MERRILL, H. W. RICKETT, W. ROBYNS, / T. A. SPRAGUE, Members of
the Editorial Committee / F. A. STAFLEU, Secretary of the Committee / AVEC
UNE TRADUCTION FRANÇAISE / PAR / CH. BAEHNI / — / 1952 / UTRECHT
— NETHERLANDS / Published with financial support of I.U.B.S. by the / Inter-
national Bureau for Plant Taxonomy and Nomenclature of the / International
Association for Plant Taxonomy / The Chronica Botanica Co. : Waltham, Mass.
U.S.A.

In 8°; p.p. [l]-228; Regnum Vegetabile, A Series of Handbooks for the use of Plant
Taxonomists and Plant Geographers, Volume 3. Issued September 1952. Mostly referred to
as ‘Stockholm Code’.

INTERNATIONAL CODE / OF / BOTANICAL NOMENCLATURE / ADOPTED
BY / THE EIGHTH INTERNATIONAL BOTANICAL / CONGRESS, PARIS, JULY
1954 / PREPARED AND EDITED BY / J. LANJOUW, Chairman, / CH. BAEHNI,
W. ROBYNS, R. C. ROLLINS, R. ROSS, / J. ROUSSEAU, G. M. SCHULZE, A. C.
SMITH, R. DE VILMORIN, Members, / F. A. STAFLEU, Secretary of the Editorial
Committee / [I.A.P.T. emblem] / 1956 / UTRECHT — NETHERLANDS / Pub-
lished with financial support of I.U.B.S.—U.N.E.S.C.O. by the / International Bureau
for Plant Taxonomy and Nomenclature / of the International Association for Plant
Taxonomy /

In 8°; pp. [l]-338; Regnum Vegetabile, A Series of Handbooks for the use of Plant
Taxonomists and Plant Geographers, Volume 8. Issued December 1956. With similar French,
German and Spanish title pages on pp. [2], [4] and [5]. Mostly referred to as ‘Paris Code’.

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[ Not present in this edition ]

[ sic ]

[ supposed to be superscript ]