(echinacea) A genus of nine species of flowering plants in the Family Asteraceae, all native to eastern North America. These are herbaceous, drought-tolerant perennial plants growing to 1 or 2 m in height. The leaves are lanceolate to elliptic, 10-20 cm long and 1.5-10 cm broad. Like all Asteraceae, the flowers are a composite inflorescence, with purple (rarely yellow or white) florets arranged in a prominent, somewhat cone-shaped head; "cone-shaped" because the petals of the outer ray florets, once the flower head opens, tend to point downward (are decumbent), thus forming a cone. Extracts from the plants, especially Echinacea angustifolia, Echinacea pallida, and Echinacea purpurea, increase the non-specific activity of the immune system.

(echinacea) A genus of perennial herbs used topically and internally. It contains echinacoside, GLYCOSIDES; INULIN; isobutyl amides, resin, and SESQUITERPENES.

(echinacea) An herb native to North America that has been used to prevent and treat the common cold and other respiratory infections. Echinacea may interfere with treatment that uses the immune system to fight cancer. The scientific names are Echinacea purpurea and Echinacea angustifolia.

Echinacea, a North American wildflower, contains a variety of biologically active substances.