CHAPTER II. Status, typification, and priority of names
SECTION 2. Typification
- 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.
- Terms such as “holotype”, “syntype”, and “lectotype”, as presently defined in Art. 9, although not applicable, strictly speaking, to the types of names in ranks higher than species, have been so used by analogy.
- 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. 22.6, 40.1, and 40.3) or designated by the author of the name; or (b) the name was sanctioned, 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simultaneously published species name was definitely included, a type must be otherwise chosen, but the choice is to be superseded if it can be demonstrated that the selected type is not conspecific with any of the material associated with either the protologue or the sanctioning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.
- The genus Anacyclus, as originally circumscribed by Linnaeus (1753), comprised three validly named species. Cassini (in Cuvier, Dict. Sci. Nat. 34: 104. 1825) designated Anthemis valentina L. (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. (1753), “the only one of the three original species still retained in the genus”, as the “standard species” (see Art. 7 Ex. 13), 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 ultimate type of the generic name.
- Castanella Spruce ex Benth. & Hook. f. (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 (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. (1896), because the latter is not a “previously or simultaneously published species name”.
- 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.
- The protologue of Elodes Adans. (1763) includes references to “Elodes” of Clusius (1601), “Hypericum” of Tournefort (1700), and Hypericum aegypticum L. (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. (1759) as the type (see Robson in Bull. Brit. Mus. (Nat. Hist.), Bot. 5: 305, 336. 1977).
- 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.
- 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.
- Physconia Poelt (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 (1979), the name now cited in the type entry in App. III.
- Pseudolarix Gordon (1858) was conserved with a specimen from the Gordon herbarium (K No. 3455) as its conserved type. As 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.
- The author who first designates (Art. 7.9 and 7.10) a type of a name of a genus or subdivision of a genus must be followed, but the choice may be superseded if (a) it can be shown that it is in serious conflict with the protologue (or with the sanctioning treatment in the case of names typified from the sanctioning work, Art. 10.2(b)), or (b) that it was based on a largely mechanical method of selection.
- Fink (in Contr. U.S. Natl. Herb. 14(1): 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(b). 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(1): 428. 1952), stated a different type, B. atropurpurea (Schaer.) A. Massal.
- Authors following the American Code of Botanical Nomenclature, Canon 15 (in Bull. Torrey Bot. Club 34: 172. 1907), designated as the type “the first binomial species in order” eligible under certain provisions. This method of selection is to be considered as largely mechanical. Thus the first type designation for Delphinium L., by Britton (in Britton & Brown, Ill. Fl. N. U.S., ed. 2, 2: 93. 1913), who followed the American Code and chose D. consolida L., has been superseded under Art. 10.5(b) by the designation of D. peregrinum L. by Green (in Sprague, Nom. Prop. Brit. Bot.: 162. 1929).
- The type of a name of a family or of any subdivision of a family is the same as that of the generic name on which it is based (see Art. 18.1). For purposes of designation or citation of a type, the generic name alone suffices. The type of a name of a family or subfamily not based on a generic name is the same as that of the corresponding alternative name (Art. 18.5 and 19.8).
- The principle of typification does not apply to names of taxa above the rank of family, except for names that are automatically typified by being based on generic names (see Art. 16), the type of which is the same as that of the generic name.
- For the typification of some names of subdivisions of genera see Art. 22.6.