Plum

A plum or gage is a stone type of fruit tree in the genus Prunus, subgenus Prunus. The subgenus is distinguished from additional subgenera (peaches, cherries, bird cherries, etc) in the shoots containing a terminal bud and the side buds solitary (not clustered), the flowers being grouped 1-5 together on short stems, and the fruit containing a groove running down one side, and a smooth stone.