Sour cherry, is a species of Prunus in the subgenus Cerasus (cherries), native to much of Europe and southwest Asia. It is closely related to the wild cherry (P. avium), also known as sweet cherry, but has a fruit that is more acidic and so is useful primarily for cooking.
The tree is smaller than the wild cherry (growing to a height of 4–10 m), has twiggy branches, and its crimson-to-near-black cherries are borne upon shorter stalks.
There are two varieties of the sour cherry: the dark-red morello cherry and the lighter-red amarelle cherry.