A plum is a fruit of some species in Prunus. Dried plums are often called prunes, though in the United States they may be labeled as ‘dried plums’, especially during the 21st century.

Plums are a diverse group of species. The commercially important plum trees are medium-sized, usually pruned to 5–6 meters (16–20 ft) height. The tree is of medium hardiness. Without pruning, the trees can reach 12 meters (39 ft) in height and spread across 10 meters (33 ft). They blossom in different months in different parts of the world; for example, in about January in Taiwan and early April in the United Kingdom.