plum, common name for a tree of any of many species of the genus Prunus of the family Rosaceae (rose family) and for its fruit, a drupe. The plum is generally cultivated in the temperate zones, though among the numerous varieties and hybrids are types suitable for many soils and sites. Of the plum's more than 100 species 30 are native to North America. It has been cultivated since prehistoric times, longer perhaps than any other fruit except the apple. Alexander the Great is said to have introduced it into Greece from Syria or Persia, where the damson plum had long been grown. The name damson is now applied to several varieties of Prunus domestica, the common garden plum of European or SW Asian origin, e.g., P. domestica var. insititia and others having small leaves and small, oval fruits usually borne in clusters. The fruits are generally tart and are favored for preserves. The greengages and prune plums are also varieties of P. domestica. Populations of plum trees that grow in the wild usually revert to the damson type. In the United States the wild red plum ( P. americana ) is found along streams and in thickets from New York to the Rocky Mts. Its small, sweet fruit has a purple bloom. This plum was utilized by Native Americans, who ate it raw, cooked, and dried; when dried it was a staple article of diet. Plum butter is made from it. Another American variety is the beach plum, or shore plum ( P. maritima ), a low-growing shrub common along the eastern coast, especially on Cape Cod, where the gathering of fruit for jelly and preserves became a commercial project. Most of the cultivated plums in the United States are derived from European and Japanese varieties (e.g., P. salicina, introduced by Burbank into the United States from Japan in 1870), although some good ones have come from native species and are valuable in that they thrive in the extreme north and south. The myrobalan, or cherry plum ( P. cerasifera ), is often used as an understock in plum cultivation. The European plum may be an ancient natural hybrid of this and another Middle Eastern species. The typical plum tree is low and wide-spreading and is one of the earliest fruit trees to bloom. In Japan, where there are many famous plum gardens, the feathery blossoms are much used in decoration. The plum is also of ornamental value in the United States, many of the varieties so used having red or purple foliage and double white, pink, or lilac flowers. The plum is closely related to the almond, apricot, cherry, and other species of the genus Prunus; a number of apricot-plum hybrids, such as the plumcot, Pluot, and Aprium, have been developed. Plums are classified in the division Magnoliophyta, class Magnoliopsida, order Rosales, family Rosaceae.