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 maximowiczii leaves of "P. maximowiczii" are green; and those from the fruit, a dark grey to green. Chemically, amygdalin and prunasin, the derivatives of which produce prussic acid as well as Genistein can be extracted from "P. maximowiczii". Prunus maximowiczii Prunus maximowiczii, known as Korean cherry, Korean mountain cherry, or Miyama cherry, is a small (about 7.5 m), fruiting cherry tree that can be found growing wild in northeastern Asia and Eurasia. The species was first described in 1857 by Franz Josef Ruprecht. It was treated in the genus "Cerasus" (now generally accepted as a subgenus of "Prunus") by Vladimir Leontyevich