In botanical nomenclature, variety (abbreviated var.; in Latin: varietas) is a taxonomic rank below that of species and subspecies, but above that of form. As such, it gets a three-part infraspecific name. It is sometimes recommended that the subspecies rank should be used to recognize geographic distinctiveness, whereas the variety rank is appropriate if the taxon is seen throughout the geographic range of the species.
The pincushion cactus, Escobaria vivipara (Nutt.) Buxb., is a wide-ranging variable species occurring from Canada to Mexico, and found throughout New Mexico below about 2,600 metres (8,500 ft). 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.
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 as follows: "Variety (varietas) the category in the botanical nomenclatural hierarchy between species and form (forma)". However the code 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 (if brought into contact).
4.1. If a greater number of ranks of taxa is desired, [...a]n organism may thus be assigned to taxa of the following ranks (in descending sequence): [... genus, ... species, subspecies,] variety (varietas), subvariety (subvarietas), form (forma), and subform (subforma). ... 4.3. Further ranks may also be intercalated or added, provided that confusion or error is not thereby introduced.
An epithet is a name. In taxonomic nomenclature, it is a word or phrase (epithet) in the name of an organism. It can be:
Epithet may also refer to:
a specific epithet:
the second part of a species name in binomial nomenclature in any branch of biology
in botany, the second part of a botanical name
Specific epithet (zoology), also called the specific name, meaning the second part of the species name or binomen
a genus, epithet
a subgenus, epithet
in botanical nomenclature:
a Section (botany), epithet
a Series (botany), epithet
a variety (botany), epithet
a forma (botany), epithet
a cultivar, epithet
a cultivar group epithet, for plants within a species that share characteristics
a grex (horticulture) epithet for cultivated orchids, according to their parentageForm (botany)
In botanical nomenclature, a form (forma, plural formae) is one of the "secondary" taxonomic ranks, below that of variety, which in turn is below that of species; it is an infraspecific taxon. If more than three ranks are listed in describing a taxon, the "classification" is being specified, but only three parts make up the "name" of the taxon: a genus name, a specific epithet, and an infraspecific epithet.
The abbreviation "f." or the full "forma" should be put before the infraspecific epithet to indicate the rank. It is not italicised.
Acanthocalycium spiniflorum f. klimpelianum or
Acanthocalycium spiniflorum forma klimpelianum (Weidlich & Werderm.) Donald
Crataegus aestivalis (Walter) Torr. & A.Gray var. cerasoides Sarg. f. luculenta Sarg. is a classification of a plant whose name is:
Crataegus aestivalis (Walter) Torr. & A.Gray f. luculenta Sarg.A form usually designates a group with a noticeable morphological deviation. The usual taxonomic practice is that the individuals classified within the form are not necessarily known to be closely related (they may not form a clade). For instance, white-flowered plants of species that usually have coloured flowers can be grouped and named (e.g., as "f. alba"). Formae apomicticae are sometimes named among plants that reproduce asexually, by apomixis. There are theoretically countless numbers of forms based on minor genetic differences, and only a few that have particular significance are likely to be named.Index of evolutionary biology articles
This is a list of topics in evolutionary biology.Plant variety
Plant variety may refer to
Variety (botany), a taxonomic nomenclature rank in botany, below subspecies, but above subvariety and form
Plant variety (law), a non-taxonomic, exclusively legal term
An informal and ambiguous substitute for form (botany) (a taxonomic nomenclature rank in botany, below variety (botany))
An older substitute for cultivar or hybrid (biology), now discouraged by the International Code of Nomenclature for Cultivated Plants. It is still used especially with regard to grapes and rice.Subspecies
In biological classification, the term subspecies refers to one of two or more populations of a species living in different subdivisions of the species' range and varying from one another by morphological characteristics.
A single subspecies cannot be recognized independently: a species is either recognized as having no subspecies at all or at least two, including any that are extinct. The term may be abbreviated to subsp. or ssp. The plural is the same as the singular: subspecies.
In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In botany and mycology, under the International Code of Nomenclature for algae, fungi, and plants, other infraspecific ranks, such as variety, may be named. In bacteriology and virology, under standard bacterial nomenclature and virus nomenclature, there are recommendations but not strict requirements for recognizing other important infraspecific ranks.
A taxonomist decides whether to recognize a subspecies or not. A common criterion for recognizing two distinct populations as subspecies rather than full species is the ability of them to interbreed without a fitness penalty. In the wild, subspecies do not interbreed due to geographic isolation or sexual selection. The differences between subspecies are usually less distinct than the differences between species.