Digitalis

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Digitalis, genus of plants of the figwort family. One species introduced from Europe, the common foxglove, is a self-seeding biennial or perennial herb, widely grown in gardens and naturalized along roadsides and in meadows or logged-off areas, especially in the western United States. The naturalized plant bears a showy, terminal cluster of hanging, tubular, spotted, purple flowers. Cultivated varieties are of various colors and markings. The erect stems are about 91 cm (about 36 in) tall with numerous large, thick leaves at the base.

Digitalis, a drug prepared from digitalin, a glycoside obtained from the common foxglove, is used in medicine. With techniques of modern pharmacology, about a dozen steroid glycosides have been isolated from the leaves. The best known of these exert a twofold action on the heart that results in a more effective heartbeat. These medicines strengthen the force of contraction and, at the same time, slow the beat so that the period of relaxation between beats is lengthened. The heart muscle thus obtains more rest even though it is working harder.

Poisoning may occur in humans or grazing animals if more than a small amount of the glycoside enters the system. Symptoms of poisoning include nausea, diarrhea, abdominal pain, and gross disturbances in heartbeat and pulse. In sufficient amounts, digitalis can lead to convulsions and death.

Scientific classification: The genus Digitalis belongs to the family Scrophulariaceae. The common foxglove is classified as Digitalis purpurea.

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