Plums are a diverse group of species. The commercially important plum trees are medium-sized, usually pruned to 18 feet height. The tree is of medium hardiness. Fruits are usually of medium size, between 1 and 3 inches in diameter, globose to oval. The flesh is firm and juicy. The fruit’s peel is smooth, with a natural waxy surface that adheres to the flesh. The plum is a drupe, meaning its fleshy fruit surrounds a single hard seed. The taste of the plum fruit ranges from sweet to tart; the skin itself may be particularly tart. It is juicy and can be eaten fresh or used in jam-making or other recipes. Plum juice can be fermented into plum wine. Dried plums (or prunes) are also sweet and juicy and contain several antioxidants. Plums and prunes are known for their laxative effect.