Variety (botany)

The pincushion cactus, Escobaria vivipara, is a wide-ranging variable species occurring from Canada to Mexico, and found throughout New Mexico below about . Nine varieties have been described. Where the varieties of the pincushion cactus meet, they intergrade. The variety Escobaria vivipara var. arizonica is from Arizona, while Escobaria vivipara var. neo-mexicana is from New Mexico. ==Definitions==

The term is defined in different ways by different authors. However, the International Code of Nomenclature for Cultivated Plants, while recognizing that the word "variety" is often used to denote "cultivar", does not accept this usage. Variety is defined in the code for cultivated plants as follows: "Variety (varietas) the category in the botanical nomenclatural hierarchy between species and form (forma)". The code for cultivated plants acknowledges the other usage as follows: "term used in some national and international legislation for a clearly distinguishable taxon below the rank of species; generally, in legislative texts, a term equivalent to cultivar. See also: cultivar and variety (varietas)". A variety will have an appearance distinct from other varieties, but will hybridize freely with those other varieties. ==Other nomenclature uses==

• In plant breeding nomenclature, at least in countries that are signatory to the UPOV Convention, "variety" or "plant variety" is a legal term. • In zoological nomenclature, the only allowed rank below that of species is that of subspecies. A name that was published before 1961 as that of a variety is taken to be the name of a subspecies. A name published after 1960 as that of a variety does not formally exist. In zoology, forms and morphs are used informally if needed, but are unregulated by the ICZN. • The bacteriological nomenclature uses the term subspecies. Some names were published as "varieties" before 1992 but the terminology is now disallowed; names that were published as varieties are taken to be published as subspecies. • In viticulture nomenclature, what is referred to as "grape varieties" are in reality cultivars according to usage in the International Code of Nomenclature for Cultivated Plants or "plant varieties" in the legal sense rather than botanical taxonomy varieties, since they are propagated by cuttings and have properties that are not stable under sexual reproduction. However, usage of the term variety is so entrenched in viticulture that a change to cultivar is unlikely. ==See also==