Prunus apricots, of cherries, and of plums, all of which have cultivars developed for commercial fruit and nut production. The almond is not a true nut, the edible part is the seed. Other species are occasionally cultivated or used for their seed and fruit. A number of species, hybrids, and cultivars are grown as ornamental plants, usually for their profusion of flowers, sometimes for ornamental foliage and shape, and occasionally for their bark. The Tree of 40 Fruit has forty varieties grafted on to one rootstock. Species such as blackthorn ("Prunus spinosa"), are grown for hedging, game cover, and other utilitarian
Prunus serrulata of the world. Numerous cultivars have been selected, many of them with double flowers with the stamens replaced by additional petals. In cultivation in Europe and North America, it is usually grafted on to "Prunus avium" roots; the cultivated forms rarely bear fruit. It is viewed as part of the Japanese custom of Hanami. There are several varieties: Some important cultivars include: Prunus serrulata Prunus serrulata or Japanese cherry, also called hill cherry, oriental cherry or East Asian cherry, is a species of cherry native to China, Japan, Korea and India, and is used for its spring cherry blossom displays