Plum


Plum

There are over 200 species of deciduous or evergreen trees and shrubs in this genus, which occurs throughout northern temperate regions, the Andes of S America, and SE Asia. It includes many economically important fruit and nut trees, and numerous ornamentals that are grown mainly for their blossom. Both P. armeniaca and P. persica are probably Chinese in origin; the former reached Italy in Roman times and the latter, which has been cultivated in China for over 2500 years, was recorded in Greece as early as the fourth century BCE. Prunus dulcis is the world's most widely grown nut tree. Prunes are dried plums from cultivars of P. domestica subsp. domestica; they have large, oval, black-skinned fruits, a rich flavor, and a high sugar and finer content that allows drying without fermentation or loss of flavor. Prunes were apparently brought to France by crusaders returning from Syria; in 1856 they were taken to California, where 70 percent of the world's crop is now produced. Prunus laurocerasus, a shade-tolerant species, is extensively grown for hedging and screening. Its many cultivars include low, spreading variants that make excellent groundcovers. Prunus mume is the classic winter flowering "plum blossom", used for Japanese bonsai. Many species are used medicinally, yielding a range of therapeutic products, from emollient oils to cough cures and laxatives. The Chinese species ahve a particularly long history of use: P. armeniaca and P.mume were first mentioned in medical literature c.CE500, and references to P. japonica date back to the Han dynasty (206BCE-CE23). Most of the medicinal properties result frmo the presence of amygdalin and prunasin, which break down in water to form hydrocyanic acid (cyanide). In small amounts, the exceedingly poisonous compound stimulates respiration, improves digestion, and gives a sense of wellbeing. Also present is benzaldehyde, which gives the typical almond scent. This is now synthesized as a substitute for bitter almond oil in food flavoring. Prunus africana (African Cherry, red stinkwood), a montane forest species, entered international trade in the 1960s, when it was found to contain a liposoluble complex, whcih has proved effective in treating prostate glad enlargement. The bark has long been used by traditional healers, but large-scale demand and destructive harvesting have led to serious depletion of wild populations, especially in Cameroon. Prunus africana received international protection as an endangered species in 1997; plantations have been established in Kenya to provide material for the pharmaceutical industry, and the propagation technique of marcotting has been used successfully to increase stocks. The fruit stalks of P. avium (wild cherry, gean) and P. cerasus (sour cherry) are infused to make a diuretic astringent remedy for cystitis, edema, and diarrhea. Prunus serotina was used by the Cherokee people to relieve labor pains, and first listed in the U.S. Pharmacopoeia in 1820 as a sedative and anti-tussive. It is still widely used, in the form of wild cherry syrup, in cough remedies.

Variable, sometimes spiny, deciduous tree with elliptic to oblong leaves, to 10cm (4in) long. Clusters of white flowers, to 2.5cm (1in) across, appear in spring, followed by ovoid to rounded yellow, red, purple, or blue-black fruits, with yellow or green flesh. Possibly originated as a cross between P. spinosa and P. cerasifera.


Common Name:
Plum
Botanical Name:
Prunus domestica
Genus:
Prunus
Family:
Rosaceae
Native Location:
Eurasia
Cultivation:
Well-drained, neutral to alkaline soil in sun. Prunus laurocerasus tolerates shade. Prunus spinosa (blackthorn) is a useful plant for hedging in cold, exposed, or coastal ares. Prune fruiting specimens in summer to restrict growth and encourage formation of fruit buds. Trim P. laurocerasus in spring. Leaves and young shoots are often attacked by aphids and caterpillars. Likely diseases and disorders include peach leaf curl, bacterial canker, chlorosis, witches' broom, and honey fungus. Many Prunus species are relatively short-lived. P. laurocerasus may be affected by leafspot and powdery mildew. Most Prunus species are shallow-rooted and will sucker if roots are damaged. Early-flowering species are prone to frost damage.
Propagation:
By seed sown in autumn (species only); by greenwood cuttings in early summer (deciduous species); by semi-ripe cuttings in summer (P. laurocerasus). Cultivars are budded in summer or grafted in early spring.
Harvest:
Leaves (P. persica) are picked in summer and dried for infusions, or (P. laurocerasus) distilled for aqueous extract (cherry laurel water). Bark (P. africana, P. persica, P. serotina) is stripped in autumn and winter and dried for infusions, liquid extracts, powders, syrups, and tinctures; bark of P. africana is also processed for pharmaceutical extracts. Flowers (P. persica) are gathered in spring, and unripe fruits (P. armeniaca, P. domestica, P. mume, P. persica) in summer, and dried for decoctions. Fruits are picked ripe or unripe, depending on use; prunes (cultivars of P. domestica) are often left on the trees to dry. Seeds from ripe fruits are dried for decoctions (P. japonica) or crushed for oil (P. armeniaca, P. dulcis, P. persica).
Varieties:
Mirabelle
Bears yellow, pit-free fruits with a bloomed skin and sweet, firm, pale, yellow flesh; ideal for conserves, spirits, and prunes.
Prune d' Agen
Bears long ovoid, dark purple fruits with very sweet aromatic flesh; good for desserts and drying as prunes.
Height:
10-12m (30-40ft)
Width:
8-10m (25-30ft)
Hardiness:
Z5-8
Parts Used:
Dried fruits (prunes).
Properties:
A cooling, lubricant, laxative herb.
Vitamin Content:
Thiamin
Medicinal Uses:
Internally for constipation. Often added to laxative preparations.
Culinary Uses:
Prunes are eaten dried, soaked or cooked, preserved in brandy or vinegar, and made into liqueurs and spirits, such as slobovitz; also added to sauces and stews (especially the Middle Eastern tadjub ahmar), stuffings, desserts, and cakes.
Economic Uses:
Due to their moisture-holding properties, prunes are used in commercial fat and egg substitutes for baked products.
Warning:
All parts of P. laurocerasus, notably the leaves and seeds, are harmful if eaten. Bitter-tasting kernels of Prunus species may be fatally toxic in excess.
Bibliography:
The Encylopedia of Herbs by Deni Bown Copyright © 1995, 2001 Dorling Kindersley Limited pp. 331-332