The lists of cultivars in the table below are indices of plant cultivars, varieties, and strains. A cultivar is a plant that is selected for desirable characteristics that can be maintained by propagation. Some of the lists use the word variety instead of cultivar. In most of these lists, variety refers to a cultivar that is recognised by the International Union for the Protection of New Varieties of Plants (UPOV). A cultivar must meet certain criteria in order to be recognised by UPOV as a named variety.