Prunus domestica subsp. insititia, or sometimes Prunus insititia. The rather tart quetsche or ‘plum of Damascus’ was introduced in Western Europe by the Romans, and today is grown in Alsace, the Franche-Comté and Lorraine. It is rarely eaten raw but are frequently used in the kitchen for tarts or cooked with meat or game dishes.
The curious name for them in French is said to derive from Luxembourgeoise Zwetsche
Image by Olivier Bacquet