The sour cherry (Prunus cerasus), also called tart cherry, is a species of cherry that is closely related to the sweet cherry, but has a fruit that is more acidic. Its sour pulp is edible.
Sour cherries are prized for desserts, especially pies and jams, where their tartness can be balanced by other sources of sweetness. They are also often used for sauces, where a sweet cherry would add too much sweetness to the final dish.
There are two main varieties of the sour cherry: the dark-red Morello cherry and the lighter-red Amarelle cherry.