Plum

Prunus domestica (sometimes referred to as Prunus × domestica) is a Prunus species with many varieties. These are often called "plums" in common English, though not all plums belong to this species. Its hybrid parentage is believed to be Prunus spinosa and Prunus cerasifera var. divaricata. 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 flowers, borne in early spring. The fruit varies in size, but can be up to 8 cm across, and is usually sweet, but can be rather acid in some varieties. (Wiki)