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 pumila leathery, long, with a serrated margin. The flowers are in diameter with five white petals and 25–30 stamens. They are produced in small clusters of two to four. The fruit is a small cherry diameter, ripening dark purple in early summer. "Prunus × cistena" (purple leaf sand cherry) is a hybrid of "Prunus cerasifera" (Cherry Plum) and "Prunus pumila". It was developed by Niels Ebbesen Hansen of South Dakota State University in 1910. Prunus pumila Prunus pumila, commonly called sand cherry, is a North American species of cherry in the rose family. It is widespread in eastern and central Canada