sour cherry

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A deciduous shrub or small tree (Prunus cerasus) having white flowers and tart red fruit.
2. n. The edible fruit of this plant.

Wiktionary

1. n. a species of Prunus in the subgenus Cerasus (cherries), native to much of Europe and southwest Asia, Prunus cerasus
2. n. the fruit of this tree

WordNet 3.0

1. n. acid cherries used for pies and preserves
2. n. rather small Eurasian tree producing red to black acid edible fruit
3. n. Australian tree with sour red fruit