The sour cherry (Prunus cerasus) 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 4â€“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.[ Sour cherries, unlike their sweet counterpart, are too sour for some people's tastes to be eaten fresh (although Europeans and middle easterners regularly eat them fresh.) They are used in cooking, especially in soups and pork dishes, and pies. Also dried sour cherries are commonly used in cooking. They are also used in combination with sugar, which balances the acidity and brings out the fruit's aroma and flavor. Thus a variety of liqueurs, desserts, preserves and drinks are made with sour cherries or sour cherry syrup.