Withania somnifera (L.) Dunal, winter cherry, Solanaceae, occurring in India and tropical Africa, is among the very important Indian medicinal plants. Going by the samskrit name ashwagandha, this species is projected as the Indian answer to ginseng. This is the sole or the chief ingredient of rejuvenating medicines, known for narcotic and sedative properties.

The plants are shrubs. The flowers are not so conspicuous (Withania somnifera1), but the red berries in inflated balloon-like calyces (Withania somnifera2) make identification of the species easy.

In India, the bruised leaves and ground roots are applied on painful swellings, carbuncles and ulcers, for its sedative action. In Africa, the roots and leaves are used internally, and the freshly pounded leaves externally, against fever, chills, rheumatism, colic, etc. The juice of the plant is a diuretic and emmenagogue. Also considered as narcotic and antiepileptic. The roots have an antifertility activity in females.

The roots contain choline, tropanol, pseudotropanol, 3-tigloyl-hydroxy-tropane, cuscohygrine, isopelletierine, anaferine, withasomnin, and anhygrine. Roots also contain tropine and pseudotropine. The leaves contain withaferine. In addition, nicotine, somniferine, somniferinine, withanine, withananine and pseudowithanine, were reported from the roots/leaves. The alkaloid content of the tissues is high, but the actual yield is low, as the alkaloids resinify during extraction.

Withaferine has distinct sedative action and induces sleep and narcosis in high doses. It also has antibacterial, antifungal and antitumour activity.

Some taxonomists consider that the cultivated plants are taxonomically different from the wild ones and so treat the cultivated one as Withania ashwagandha Kaul. It is believed that the therapeutic activity of the wild and cultivated samples also differs, in spite of similar alkaloids.

The berries of another species, Withania coagulans (L.) Dunal (Indian rennet), coagulate milk due to an enzyme and used in making cheese. This species occurs in north India, particularly in Punjab. The fruits are emetic, sedative, and diuretic, useful in liver complaints. The dried fruits are used in intestinal disorders particularly of the liver. Fruits are also used in asthma and in preventing atherosclerosis.

In the north Indian markets, no distinction seems to be made between the fruits of different species.