CHAPTER III. Nomenclature of taxa according to their rank
SECTION 1. Names of taxa above the rank of family
- The name of a taxon above the rank of family is treated as a noun in the plural and is written with an initial capital letter. Such names may be either (a) automatically typified names (Art. 10.7), formed from the name of an included genus in the same way as family names (Art. 18.1; but see Art. 16.4) by adding the appropriate rank-denoting termination (Art. 16.3 and 17.1), preceded by the connecting vowel -o- if the termination begins with a consonant; or (b) descriptive names, not so formed, which may be used unchanged at different ranks.
- Automatically typified names above the rank of family: Lycopodiophyta, based on Lycopodium; Magnoliophyta, based on Magnolia; Gnetophytina, based on Gnetum; Pinopsida, based on Pinus; Marattiidae, based on Marattia; Caryophyllidae and Caryophyllales, based on Caryophyllus; Fucales, based on Fucus; Bromeliineae, based on Bromelia.
- Descriptive names above the rank of family: Anthophyta, Chlorophyta, Lycophyta, Parietales; Ascomycota, Ascomycotina, Ascomycetes; Angiospermae, Centrospermae, Coniferae, Enantioblastae, Gymnospermae.
- For automatically typified names, the name of the subdivision or subphylum that includes the type of the adopted name of a division or phylum, the name of the subclass that includes the type of the adopted name of a class, and the name of the suborder that includes the type of the adopted name of an order are to be based on the same generic name (see also Art. 16.4) as the corresponding higher-ranked name.
- Automatically typified names end as follows: the name of a division or phylum ends in -phyta, unless it is referable to the algae or fungi in which case it ends in -phycota or -mycota, respectively; the name of a subdivision or subphylum ends in -phytina, unless it is referable to the algae or fungi in which case it ends in -phycotina or -mycotina, respectively; the name of a class in the algae ends in -phyceae, and of a subclass in -phycidae; the name of a class in the fungi ends in -mycetes, and of a subclass in -mycetidae; the name of a class in the plants ends in -opsida, and of a subclass in -idae (but not -viridae).
Automatically typified names not in accordance with these terminations or those in Art. 17.1 are to be corrected, without change of the author citation or date of publication (see Art. 32.2). However, if such names are published with a non-Latin termination they are not validly published.
- “Cactarieae” (Dumortier, 1829, based on Cactus) and “Coriales“ (Lindley, 1833, based on Coriaria), both published for taxa of the rank of order, are to be corrected to Cactales Dumort. (1829) and Coriariales Lindl. (1833), respectively.
- However, Acoroidées (Kirschleger, Fl. Alsace 2: 103. 1853–Jul 1857), published for a taxon of the rank of order, is not to be accepted as “Acorales Kirschl.”, as it has a French rather than a Latin termination. The name Acorales was later validly published by Reveal (in Phytologia 79: 72. 1996).
- The terms “divisio” and “phylum”, and their equivalents in modern languages, are treated as referring to one and the same rank. When “divisio” and “phylum” are used simultaneously to denote different non-consecutive ranks, this is to be treated as informal usage of rank-denoting terms (see Art. 37 Note 1 and 37.8).
- In ranks higher than order, the word elements -clad-, -cocc-, -cyst-, -monad-, -mycet-, -nemat-, or -phyt-, being the genitive singular stem of the second part of a name of an included genus, may be omitted before the rank-denoting termination. Such names are automatically typified when their derivation is obvious or is indicated in the protologue.
- The name Raphidophyceae Chadef. ex P. C. Silva (1980) was indicated by its author to be based on Raphidomonas F. Stein (1878). The name Saccharomycetes G. Winter (1881) is regarded as being based on Saccharomyces Meyen (1838). The name Trimerophytina H. P. Banks (1975) was indicated by its author to be based on Trimerophyton Hopping (1956).