Amygdalus

Amygdalus 

(almond), a genus of plants of the family Rosaceae. They are small trees or shrubs. The solitary flowers are white or pink. The fruit is a drupe, which splits at maturity into two valves; it has a dry, usually pubescent pericarp. The smooth, reticularly furrowed or perforate stone (almond) separates itself from the pericarp and has a thick hard or brittle shell. The seed, or kernel, is either bitter (owing to the presence of up to 4 percent amygdalin) or sweet and has a scarious testa.

There are approximately 40 known species, distributed in Southwest, Middle, and Southeast Asia, in southwestern North America, and in northwestern Central America. In the USSR there are 13 species (according to other sources, 17). Most species grow in deserts and on dry, rocky mountain slopes up to 2,000 m above sea level. In the USSR wild varieties of Amygdalus grow in the southern steppe and in arid mountain regions of Middle Asia and Transcaucasia. The almond (Amygdalus cornmunis) is cultivated in many countries. In the USSR it is grown in Moldavia, the Crimea, Transcaucasia, and Middle Asia.

The Amygdalus grow best on loose limestone soils; they do not tolerate acid, extremely wet, or saline soils. The plants are photophilic, drought resistant, and relatively winter-hardy. Fruiting occurs the third or fourth year after grafting, and the harvest is more than 400 kg per hectare. The dry kernel contains on the average 54 percent fats, 21 percent nitrogenous substances, 13 percent non-nitrogenous substances, 4 percent cellulose, 6 percent water, and 2 percent ash.

The fruits of sweet varieties of Amygdalus are eaten fresh, used in the confectionery industry, and processed for their almond oil. The shell is used to color wines and in the production of cognac. Almond oil is used as a mild laxative and in ointments. The oil cakes (siftings) are used as a skin softener. The oil cake of bitter Amygdalus yields bitter-almond water, which is used in drops and mixtures as a mild pain reliever. The wood is used in wood-working. Forms of Amygdalus with polypetalous flowers are grown as ornamentals. The best varieties in the USSR are Yalta, Paper-shell, Desertnyi, and Prianyi. The plants are propagated primarily by budding. Seedlings of Amygdalus, peach, plum, and cherry plum serve as stocks.

REFERENCE

Orekhoplodovye drevesnye porody. Moscow, 1969.

A. A. RIKHTER