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 pseudocerasus has been cultivated for its edible (if tart) fruit for around 2000 years. In Japan it is favored as an ornamental tree for its tendency to bloom, flowers before leaves, earlier than the Japanese cherry "Prunus serrulata". A tetraploid with 2n=32 chromosomes, it is used as rootstock for other flowering cherries. It is the parent of a number of hybrid cultivars. It is resistant to the fungal disease cherry leaf spot. Prunus pseudocerasus Prunus pseudocerasus or Prunus pseudo-cerasus, the Chinese sour cherry or just Chinese cherry, is a species of cherry native to China and is used worldwide as an