Cultivar
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In botany, a cultivar is a cultivated selection of a plant species that is vegetatively propagated, i.e, a clone. They may be either particularly desirable selections from populations of a single species, or hybrids between species. The word cultivar is a portmanteau coined from "cultivated" and "variety".
Cultivars are identified by uniquely distinguishing names, which may be registered and trademarked. Names of cultivars are regulated by the International Code for the Nomenclature of Cultivated Plants (ICNCP) and registered with an International Cultivar Registration Authority and conform to the rules of the ISHS Commission Nomenclature and Cultivar Registration. There are authorities for different plant-groups.
A cultivar name is indicated by using the abbreviation cv. and/or single-quoting the cultivar name. A cultivar is ascribed to a particular species, or, if of hybrid or unknown origin, just to a genus. Cultivar names before 1 January 1959 were often given in Latin form and can be readily confused with names of botanical taxa, but after that date, must be in a modern vernacular language to distinguish them from botanical names. Cultivar names, unlike genus and species names, are not italicised; they are also capitalised.
- Berberis thunbergii cv. 'Crimson Pygmy'
- Cryptomeria japonica 'Elegans'
- Rosa cv. Peace:
- Chamaecyparis lawsoniana 'Aureomarginata' (pre-1959 name, Latin in form)
- Chamaecyparis lawsoniana 'Golden Wonder' (post-1959 name, English language)
- Pinus densiflora 'Akebono' (post-1959 name, Japanese language)
Where several very similar cultivars exist, these are termed Cultivar Groups; the name is in normal type and capitalised as in a single cultivar, but not in single quotes, and followed by "Group"
- Brassica oleracea Capitata Group (the group of cultivars including all typical cabbages)
- Brassica oleracea Botrytis Group (the group of cultivars including all typical cauliflowers)
Some Cultivar Groups are so well 'fixed' or established that they 'come true from seed', meaning that the plants from a seed sowing (rather than vegetatively propagated) will show very little variation. In the past, such plants were often called by the terms 'variety', 'selection' or 'strain'; these terms (particularly variety, which has a very different botanical meaning) are best avoided with cultivated plants.
Cultivars that are still being developed and not yet ready for release to retail sale are often coded with letters and/or numbers before being assigned a name.
Cultivars in the natural world
Many cultivars are "naturalized" in gardening, planted out and largely left to their own devices. With pollination and regrowth from seed, true natural processes, the distinct cultivars will disappear over time. The cultivar's genetic material however may become part of the gene pool of a population, where it will be largely but not completely swamped. Cultivars that have originated as hybrids of different species are exotic, as is a plant from a different continent. They are in itself a threat to the true type of a species.
Legal points
With plants produced by genetic engineering becoming more and more widely introduced, it is important to note that the companies producing these plants often claim a patent on their product. Therefore, according to corporate claims, the notion that any plant that occurs from seed is natural, is no longer appropriate; it can be illegal to propagate new plants from a patented cultivar. The practice of patenting living plants is however often considered unethical.
External links
- International Cultivar Registration Authorities (http://www.ishs.org/sci/icra.html)da:Cultivar