Horticultural plants of the same species that are distinctive enough to be given a name are called cultivars, which is short for "cultivated variety." A cultivar can be distinguished from other similar cultivars by some combination of characters, including appearance, color, taste, size, and pest resistance. Although the terms variety and cultivar are used interchangeably, cultivar is not the same as a botanical variety, which is a taxonomic category below the species level that can apply to both wild and cultivated plants.
According to rules for naming plants, cultivar names must be in modern languages and not italicized. The first letters are capitalized and the name is either preceded by the abbreviation cv. (cultivar) or is put in single quotes. For example, a commonly grown yellow tomato is Lycopersicon esculentum cv. Yellow Pear and a popular type of sweet corn is Zea mays 'Silver Queen.' Cultivar names can follow generic, specific, or common names.
New cultivars are usually developed from either wild ancestors or established cultivars through selective breeding, a process that has been ongoing since the domestication of plants. Desired traits can also arise through mutations and plant viruses. Modern technologies of cloning and tissue culture that allow plants to be propagated vegetatively have added greatly to the number of such cultivars now produced.
see also Breeding; Horticulture; Ornamental Plants; Species; Taxonomy.
cul·ti·var / ˈkəltəˌvär/ • n. Bot. a plant variety that has been produced in cultivation by selective breeding. Cultivars are usually designated in the style Taxus baccata “Variegata.” See also variety (sense 2).