Prunus

Prunus

Stone Fruits
Genus:	Prunus
Family:	Rosaceae
Type:	Trees, Shrubs
Disease issues:	Several, with some quite serious

Prunus is a genus of trees and shrubs traditionally placed within the rose family, (Family Rosaceae), but now sometimes placed in its own family, the Prunaceae (or Amygdalaceae), or in a subfamily of Rosaceae, the Prunoideae (or Amygdaloideae). There are several hundred species of Prunus, spread throughout the northern temperate regions of the globe.

Description

The flowers are usually white to pink, with five petals and five sepals. They are borne singly, or in umbels of two to six or more on racemes. The fruit of all Prunus species is a drupe with a relatively large stone. Leaves are simple and usually lanceolate, unlobed and toothed along the margin.

Subgenera

Some treatments break the genus up into several different genera, but this segregation is not widely recognised other than at the subgeneric rank.

Prunus subgenera:
- Subgenus Amygdalus: almonds and peaches. Axillary buds in threes (vegetative bud central, two flower buds to sides). Flowers in early spring, sessile or nearly so, not on leafed shoots. Fruit with a grove along one side; stone deeply grooved. Type species Prunus dulcis (Almond).
- Subgenus Prunus: plums and apricots. Axillary buds solitary. Flowers in early spring stalked, not on leafed shoots. Fruit with a grove along one side; stone rough. Type species Prunus domestica (Plum).
- Subgenus Cerasus: cherries. Axillary buds single. Flowers in early spring in corymbs, long-stalked, not on leafed shoots. Fruit not groved; stone smooth. Type species Prunus cerasus (Sour cherry).
- Subgenus Lithocerasus: dwarf cherries. Axillary buds in threes. Flowers in early spring in corymbs, long-stalked, not on leafed shoots. Fruit not groved; stone smooth. Type species Prunus pumila (Sand cherry).
- Subgenus Padus: bird cherries. Axillary buds single. Flowers in late spring in racemes on leafy shoots, short-stalked. Fruit not groved; stone smooth. Type species Prunus padus (European bird cherry).
- Subgenus Laurocerasus: cherry-laurels. Axillary buds single. Flowers in early spring in racemes, not on leafed shoots, short-stalked. Fruit not groved; stone smooth. Mostly evergreen (all the other subgenera are deciduous). Type species Prunus laurocerasus (European cherry-laurel).

Uses

The genus Prunus includes the almond, apricot, cherry, peach, and plum, all of which have cultivars developed for commercial fruit production. The edible part of the almond is the seed; the almond fruit is a drupe and not a "nut". There are also a number of species, hybrids, and cultivars grown strictly as ornamentals, usually for their profusion of flowers, occasionally for leaves and bark. These ornamentals include the group that may be collectively called flowering cherries.

Because of their considerable value as both food and ornamental plants, many Prunus species have been introduced to parts of the world to which they are not native. Many of the Old World species are grown for ornament or fruit, and have been planted throughout the world; and some have become naturalised beyond their native range.