Prunus domestica (sometimes referred to as Prunus × domestica) is a species of flowering plant in the family Rosaceae. A deciduous tree, it includes many varieties of the fruit trees known as plums in English, though not all plums belong to this species. The greengages and damsons also belong to subspecies of P. domestica.
Its hybrid parentage is believed to be Prunus spinosa and Prunus cerasifera. This is the most commonly grown plum at least in Europe, and most prunes (dried plums) are made from fruits of this species.
Typically it forms a large shrub or a small tree. It may be somewhat thorny, with white blossom, borne in early spring. The oval or spherical fruit varies in size, but can be up to 8 cm across, and is usually sweet (dessert plum), though some varieties are sour and require cooking with sugar to make them palatable. Like all Prunus fruits, it contains a single large seed, usually called a stone, which is discarded when eating.
Plums are grown commercially in orchards, but modern rootstocks, together with self-fertile strains, training and pruning methods, allow single plums to be grown in relatively small spaces. Their early flowering and fruiting means that they require a sheltered spot away from frosts and cold winds.
Numerous cultivars have been selected for garden use. The following have gained the Royal Horticultural Society’s Award of Garden Merit:-
The European Garden Flora recognises three subspecies, though scientific studies favour a more fine-grained separation:
The subspecies cross easily, so that numerous intermediate forms can be found: their sweetness and tartness may vary, their colours varying from bluish purple, to red, orange, yellow or light green.
The Wild Plum
The horticulturalist Edward Step had this to say about the wild plum.
The Wild Plum (Prunus communis, sub-sp. domestica) has also brown bark, its branches straight, and not ending in spines. The downiness noticed on the underside of the Bullace leaves is here restricted to the ribs of the leaf. The fruit attains a diameter of an inch or an inch and a half. Although found occasionally in hedgerows, this sub-species is not indigenous in any part of our islands. Hooker says the only country in which it is really indigenous is Western Asia; but its numerous cultivated forms are widely distributed.
Wild Plums (Prunus communis). With the single exception of the Hazel, all our native fruit-trees are members of the extensive and beautiful Rose family. Before Roman invasions brought improved and cultivated varieties, our “rude forefathers” must have been glad to eat the Sloes, Crabs, and Wild Cherries that are now regarded as too terribly crude and austere, in an uncooked condition, for any stomach but that of the natural boy, which appears capable of surviving any ill-treatment. Some authors have regarded the Wild Plum and the Bullace as being specifically distinct from the Sloe and from each other; but the modern view is that their differences only entitle them to rank as sub-species of the Sloe, and as such they will be regarded here.