CHAPTER II

STATUS, TYPIFICATION, AND PRIORITY OF NAMES

SECTION 2

TYPIFICATION

Article 10

10.1. The type of a name of a genus or of any subdivision of a genus is the type of a name of a species (except as provided by Art. 10.4). For purposes of designation or citation of a type, the species name alone suffices, i.e. it is considered as the full equivalent of its type (see also Rec. 40A.3).

Note 1. Terms such as “holotype”, “syntype”, and “lectotype”, as presently defined in Art. 9, although not applicable to the types of names at ranks higher than species, have sometimes been so used by analogy.

10.2. If in the protologue of a name of a genus or of any subdivision of a genus the holotype or lectotype of one or more previously or simultaneously published species name(s) is definitely included (see Art. 10.3), the type must be chosen from among these types, unless (a) the type was indicated (Art. 10.8, 40.1, and 40.3) or designated by the author of the name; or (b) the name was sanctioned (Art. F.3), in which case the type may also be chosen from among the types of species names included in the sanctioning treatment. If no type of a previously or simultaneously published species name was definitely included, a type must be otherwise chosen, but the choice is to be superseded if it can be demonstrated that the selected type is not conspecific with any of the material associated with either the protologue or the sanctioning treatment.

Ex. 1. The genus Anacyclus, as originally circumscribed by Linnaeus (Sp. Pl.: 892. 1753), comprised three validly named species. Cassini (in Cuvier, Dict. Sci. Nat. 34: 104. 1825) designated Anthemis valentina L. (l.c.: 895. 1753) as type of Anacyclus, but this was not an original element of the genus. Green (in Sprague, Nom. Prop. Brit. Bot.: 182. 1929) designated Anacyclus valentinus L. (l.c.: 892. 1753), “the only one of the three original species still retained in the genus”, as the “standard species” (see Art. 7 *Ex. 16), and her choice must be followed (Art. 10.5). Humphries (in Bull. Brit. Mus. (Nat. Hist.), Bot. 7: 109. 1979) designated a specimen in the Clifford Herbarium (BM) as lectotype of Anacyclus valentinus, and that specimen thereby became the type of Anacyclus.

Ex. 2. Castanella Spruce ex Benth. & Hook. f. (Gen. Pl. 1: 394. Aug 1862) was described on the basis of a single specimen collected by Spruce and without mention of a species name. Swart (in ING Card No. 2143. 1957) was the first to designate a type (as “T.”): C. granatensis Planch. & Linden (in Ann. Sci. Nat., Bot., ser. 4, 18: 365. Dec 1862), based on Linden 1360. As long as the Spruce specimen is considered to be conspecific with Linden’s material, Swart’s type designation cannot be superseded, even though the Spruce specimen became the type of Paullinia paullinioides Radlk. (Monogr. Paullinia: 173. 1896), because the latter is not a “previously or simultaneously published species name”.

10.3. For the purposes of Art. 10.2, definite inclusion of the type of a name of a species is effected by citation of, or reference (direct or indirect) to, a validly published species name, whether accepted or synonymized by the author, or by citation of the holotype or lectotype of a previously or simultaneously published species name.

Ex. 3. The protologue of Elodes Adans. (Fam. Pl. 2: 444, 553. 1763) includes references to “Elodes” of Clusius (Alt. App. Rar. Pl. Hist., App. Alt. Auct.: [7]. 1611, i.e. “Ascyrum supinum ἑλώδης”), “Hypericum” of Tournefort (Inst. Rei Herb. 1: 255. 1700, i.e. “Hypericum palustre, supinum, tomentosum”), and Hypericum aegypticum L. (Sp. Pl.: 784. 1753). The last is the only reference to a validly published species name, and neither of the other elements is the type of a species name. The type of H. aegypticum is therefore the type of Elodes even though subsequent authors designated H. elodes L. (Amoen. Acad. 4: 105. 1759) as the type (see Robson in Bull. Brit. Mus. (Nat. Hist.), Bot. 5: 305, 337. 1977).

10.4. By and only by conservation (Art. 14.9), the type of a name of a genus may be a specimen or illustration, preferably used by the author in the preparation of the protologue, other than the type of a name of an included species.

Note 2. If the element designated under Art. 10.4 is the type of a species name, that name may be cited as the type of the generic name. If the element is not the type of a species name, a parenthetical reference to the correct name of the type element may be added.

Ex. 4. Physconia Poelt (in Nova Hedwigia 9: 30. 1965) was conserved with the specimen “‘Lichen pulverulentus’, Germania, Lipsia in Tilia, 1767, Schreber (M)” as the conserved type. That specimen is the type of P. pulverulacea Moberg (in Mycotaxon 8: 310. 1979), the name now cited in the type entry in App. III.

Ex. 5. Pseudolarix Gordon (Pinetum: 292. 1858) was conserved with a specimen from the Gordon herbarium (K No. 3455) as its conserved type. Because this specimen is not the type of any species name, its accepted identity “[= P. amabilis (J. Nelson) Rehder …]” has been added to the corresponding entry in App. III.

10.5. The author who first designates (Art. 7.10, 7.11, and F.5.4) a type of a name of a genus or subdivision of a genus must be followed, but the choice may be superseded if the author used a largely mechanical method of selection (Art. 10.6). A type chosen using a largely mechanical method of selection is superseded by any later choice of a different type not made using such a method, unless, in the interval, the supersedable choice has been affirmed by its adoption in a publication that did not use a mechanical method of selection.

Note 3. The effective date of a typification (cf. Art. 22.2, 48.2 and 52.2(b)) subject to supersession under Art. 10.5 remains that of the original selection, unless the type has been superseded.

10.6. For the purposes of Art. 10.5, “a largely mechanical method of selection” is defined as one in which the type is selected following a set of objective criteria such as those set out in “Canon 15” of the so-called “Philadelphia Code” (Arthur & al. in Bull. Torrey Bot. Club 31: 255–257. 1904) or in “Canon 15” of the American Code of Botanical Nomenclature (Arthur & al. in Bull. Torrey Bot. Club 34: 172–174. 1907).

Ex. 6. The first type designation for Delphinium L. was by Britton (in Britton & Brown, Ill. Fl. N. U.S., ed. 2, 2: 93. 1913), who followed the American Code and whose selection of D. consolida L. is therefore considered to have been largely mechanical. His choice has been superseded under Art. 10.5 by the designation of D. peregrinum L. by Green (in Sprague, Nom. Prop. Brit. Bot.: 162. 1929).

10.7. Unless the author(s) specifically state that they are not using a mechanical method of type selection, the following criteria determine whether a particular publication, appearing prior to 1 January 1935, has adopted a largely mechanical method of type selection:

(a) any statement to that effect, including that the American Code or the “Philadelphia Code” was being followed or that types were determined in a particular mechanical way (e.g. the first species in order); or

(b) adoption of any provision of the “Philadelphia Code” or the American Code that was contrary to the provisions of the International Rules of Botanical Nomenclature in force at that time, e.g. the inclusion of one or more tautonyms as species names.

Additionally for publications appearing prior to 1 January 1921:

(c) if an author of the publication was a signatory of the “Philadelphia Code”¹ (and was therefore also a signatory of the American Code);

[footnote]¹ A list of the 23 signatories of the “Philadelphia Code” was published in Taxon 65: 1448. 2016, as well as in Bull. Torrey Bot. Club 31: 250. 1904.

(d) if an author of the publication stated publicly (e.g. in another publication) that in the typification of generic names the “Philadelphia Code” or the American Code was followed;

(e) if an author of the publication was an employee or a recognized associate of the New York Botanical Garden; or

(f) if an author of the publication was an employee of the United States government.

Ex. 7. (a) Fink (in Contr. U. S. Natl. Herb. 14: 2. 1910) specified that he was “stating the types of the genera according to the ‘first species’ rule”. His type designations may therefore be superseded under Art. 10.5. For example, Fink had designated Biatorina griffithii (Ach.) A. Massal. as the type of Biatorina A. Massal.; but his choice was superseded when the next subsequent designation, by Santesson (in Symb. Bot. Upsal. 12: 428. 1952), stated a different type, B. atropurpurea (Schaer.) A. Massal.

Ex. 8. (a) Underwood (in Mem. Torrey Bot. Club 6: 247–283. 1899) wrote (p. 251): “For each genus established the first named species will be regarded as type”. Therefore, his designation (p. 276) of Caenopteris furcata Bergius as type of Caenopteris Bergius (in Acta Acad. Sci. Imp. Petrop. 1782(2): 249. 1786) is supersedable; this has been effected by Copeland (Gen. Filicum: 166. 1947), who designated C. rutifolia Bergius as type.

Ex. 9. (a) Murrill (in J. Mycol. 9: 87. 1903), referring to generic types, wrote: “The principles by which I have been chiefly guided are also quite well known having been stated and explained by Underwood” [see Ex. 8]. Consequently Murrill (l.c.: 95, 98. 1903) listed the first-named species treated by Quélet (Enchir. Fung.: 175. 1886), Coriolus lutescens (Pers.) Quél., as type of Coriolus Quél. (l.c.), and later (in Bull. Torrey Bot. Club 32: 640. 1906) listed Polyporus zonatus Nees as type because it was “the first species accompanied by a correct citation of a figure”. Both lectotypifications are considered to be mechanical and were superseded by the choice of Polyporus versicolor (L.) Fr. by Donk (Revis. Niederl. Homobasidiomyc.: 180. 1933).

Ex. 10. (b) Britton & Wilson (Bot. Porto Rico 6: 262. 1925) designated Cucurbita lagenaria L. as type of Cucurbita L. (Sp. Pl.: 1010. 1753). However, because they were evidently following the American Code (they included many tautonyms in their publication, e.g. “Abrus Abrus (L.) W. Wight”, “Acisanthera Acisanthera (L.) Britton”, and “Ananas Ananas (L.) Voss”), their type selections used a largely mechanical method. Their selection of C. lagenaria (currently treated as Lagenaria siceraria (Molina) Standl.) has been superseded by the selection of C. pepo L. by Green (in Sprague, Nom. Prop. Brit. Bot.: 190. 1929).

Ex. 11. (d) In considering the typification of Achyranthes L. in a preliminary to his account of Amaranthaceae in the North American Flora, Paul C. Standley (in J. Wash. Acad. Sci. 5: 72. 1915) selected A. repens L. as type stating that “there seems, moreover, no doubt as to the type of the genus Achyranthes under the American Code of nomenclature”, noting that, as a result, “the name Achyranthes must be used in a sense other than that in which it has generally been employed in recent years”. As a result of this published statement of acceptance of the American Code, not only is Standley’s selection of A. repens superseded by that of A. aspera L. by Hitchcock (in Sprague, Nom. Prop. Brit. Bot.: 135. 1929), but types cited in Standley’s other publications (e.g. in Britton, N. Amer. Fl. 21: 1–254. 1916–1918) are supersedable under Art. 10.5. Therefore, Standley’s statement (l.c.: 134. 1917) that A. repens was the type of Achyranthes does not constitute affirmation of his earlier selection; similarly his publication of type designations previously made by Britton & Brown, such as Chenopodium rubrum L. (l.c.: 9. 1916) and Amaranthus caudatus L. (l.c.: 102. 1917), does not constitute affirmation of their selection; the typification of Chenopodium L. has been superseded by the selection of C. album L. by Hitchcock (in Sprague, Nom. Prop. Brit. Bot.: 137. 1929) and that of Amaranthus L. was first affirmed by Green (in Sprague, l.c.: 188. 1929).

10.8. When the epithet in the name of a subdivision of a genus is identical with or derived from the epithet in one of the originally included species names, the type of the higher-ranking name is the same as that of the species name, unless the original author of the higher-ranking name designated another type.

Ex. 12. The type of Euphorbia subg. Esula Pers. (Syn. Pl. 2: 14. 1806) is the type of E. esula L., one of the species names included by Persoon; the designation of E. peplus L. (also included by Persoon) as type by Croizat (in Revista Sudamer. Bot. 6: 13. 1939) has no standing.

Ex. 13. The type of Cassia [unranked] Chamaecrista L. (Sp. Pl.: 379. 1753) is the type of C. chamaecrista L., nom. rej. (App. V), one of the five species names included by Linnaeus.

10.9. The type of a name of a family or of any subdivision of a family is the same as that of the generic name from which it is formed (see Art. 18.1). For purposes of designation or citation of a type, the generic name alone suffices. The type of a name of a family or subfamily not formed from a generic name is the same as that of the corresponding alternative name (Art. 18.5 and 19.8).

10.10. The principle of typification does not apply to names of taxa above the rank of family, except for names that are automatically typified by being formed from generic names (see Art. 16.1(a)), the type of which is the same as that of the generic name.

Recommendation 10A

10A.1. When a combination at the rank of a subdivision of a genus has been published under a generic name that has not yet been typified, the type of the generic name should be selected from the subdivision of the genus that was designated as nomenclaturally typical, if that is apparent.

10A.2. In citing a type chosen using a largely mechanical method of selection that has since been affirmed by an author not using such a method, both the place of original selection and that of affirmation should be cited, e.g. “Quercus L. … Type: Q. robur L. designated by Britton & Brown (Ill. Fl. N. U.S., ed. 2, 1: 616 1913); affirmed by Green (in Sprague, Nom. Prop. Brit. Bot.: 189. 1929)”.