Article 16

16.1. 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, formed by replacing the termination -aceae in a legitimate name of an included family based on a generic name by the termination denoting their rank (preceded by the connecting vowel -o- if the termination begins with a consonant), as specified in Rec.16A.1-3 and Art. 17.1; or (b) descriptive names, not so formed, which may be used unchanged at different ranks.

Ex. 1. Automatically typified names above the rank of family: Magnoliophyta, based on Magnoliaceae; Gnetophytina, based on Gnetaceae; Pinopsida, based on Pinaceae; Marattiidae, based on Marattiaceae; Caryophyllidae and Caryophyllales, based on Caryophyllaceae; Fucales, based on Fucaceae; Bromeliineae, based on Bromeliaceae.
Ex. 2. Descriptive names above the rank of family: Anthophyta, Chlorophyta, Parietales; Ascomycota, Ascomycotina, Ascomycetes; Angiospermae, Centrospermae, Coniferae, Enantioblastae, Gymnospermae.

16.2. 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 type as the corresponding higher-ranked name.

Ex. 3. Pteridophyta Bergen & B. M. Davis (1906) and Pteridophytina B. Boivin (1956); Gnetopsida Engl. (1898) and Gnetidae Cronquist & al. (1966); Liliales Perleb (1826) and Liliineae Rchb. (1841).

16.3. When an automatically typified name above the rank of family has been published with an improper Latin termination, not agreeing with those provided for in Rec. 16A.1-3 and Art. 17.1, the termination must be changed to conform with these standards, without change of the author citation or date of publication (see Art. 32.7). However, if such names are published with a non-Latin termination they are not validly published.

Ex. 4. "Cactarieae" (Dumortier, 1829, based on Cactaceae) and "Coriales" (Lindley, 1833, based on Coriariaceae), both published for taxa of the rank of order, are to be corrected to Cactales Dumort. (1829) and Coriariales Lindl. (1833), respectively.
Ex. 5. 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).
Note 1. 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 ranks, this is to be treated as informal usage of rank-denoting terms (see Art. 33.11).

16.4. Where one of the word elements -clad-, -cocc-, -cyst-, -monad-, -myces-, -nemat-, or -phyton-, being the genitive singular stem of the second part of a name of an included genus, has been omitted before the termination -phyceae, -phycota (algae), -mycetes, -mycota (fungi), -opsida, or -phyta (other groups of plants), the shortened class name or division or phylum name is regarded as based on the generic name in question if such derivation is obvious or is indicated at establishment of the group name. These word elements may also be omitted before the termination for subdivision or subphylum as appropriate in each case.

Ex. 6. 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).
Note 2. The principle of priority does not apply above the rank of family (Art. 11.10; but see Rec. 16B).

Recommendation 16A

16A.1. A name of a division or phylum should end in -phyta unless the taxon is a division or phylum of fungi, in which case its name should end in -mycota.

16A.2. A name of a subdivision or subphylum should end in -phytina, unless it is a subdivision or subphylum of fungi, in which case it should end in -mycotina.

16A.3. A name of a class or of a subclass should end as follows:

  1. In the algae: -phyceae (class) and -phycidae (subclass);
  2. In the fungi: -mycetes (class) and -mycetidae (subclass);
  3. In other groups of plants: -opsida (class) and -idae, but not -viridae (subclass).

Recommendation 16B

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


(c) 2006, by International Association for Plant Taxonomy. This page last updated  12.03.2007 .