A plum is a drupe fruit of the subgenus Prunus of the genus Prunus. The subgenus is distinguished from other subgenera (peaches, cherries, bird cherries, etc.) in the shoots having a terminal bud and solitary side buds (not clustered), the flowers in groups of one to five together on short stems, and the fruit having a groove running down one side and a smooth stone (or pit).
Mature plum fruit may have a dusty-white coating that gives them a glaucous appearance. This is an epicuticular wax coating and is known as "wax bloom". Dried plum fruits are called dried plums or prunes, although prunes are a distinct type of plum, and may have antedated the fruits now commonly known as plums.
Plums are a diverse group of species. The commercially important plum trees are medium sized, usually pruned to 5-6 meters height. The tree is of medium hardiness. Without pruning, the trees can reach 12 meters in height and spread across 10 meters. They blossom in different months in different parts of the world; for example, in about January in Taiwan and about April in the United States. Fruits are usually of medium size, between 1 to 3 inches in diameter, globose to oval. The flesh is firm, juicy and mealy. The fruit's peel is smooth, with a natural waxy surface that adheres to the flesh. The fruit has a single large seed.
Cultivation and uses
Plum fruit tastes sweet and/or tart; the skin 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; . In central England, a cider-like alcoholic beverage known as plum jerkum is made from plums. Dried plums (or prunes) are also sweet and juicy and contain several antioxidants. Plums and prunes are known for their laxative effect. This effect has been attributed to various compounds present in the fruits, such as dietary fiber, sorbitol, and isatin. Prunes and prune juice are often used to help regulate the functioning of the digestive system. Dried prune marketers in the USA have, in recent years, begun marketing their product as "dried plums". This is due to "prune" having negative connotations connected with elderly people suffering from constipation. Dried, salted plums are used as a snack, sometimes known as saladito or salao. Various flavors of dried plum are available at Chinese grocers and specialty stores worldwide. They tend to be much drier than the standard prune. Cream, ginsing, spicy, and salty are among the common varieties. Licorice is generally used to intensify the flavor of these plums and is used to make salty plum drinks and toppings for shaved ice or baobing.Read More