senna, any plant of the genus Sennia (formerly placed in Cassia ), leguminous herbs, shrubs, and trees of the family Leguminosae ( pulse family), most common in warm regions. Some species are cultivated for ornament, but sennas are best known as medicinal plants. The dried leaves are used as a purgative and are chiefly obtained from S. acutifolia (Alexandria senna) and S. angustifolia (Indian senna) both trees are cultivated especially in S India. The wild senna ( S. marylandica ), a perennial of the E United States, has been similarly used. Golden shower ( S. fistula ) of India yields canafistula, a purgative extracted from the fruit pulp. The young shoots of several wild species are used for food and the seeds for a coffee substitute. S. nictitans, a North American herb, is sometimes called wild sensitive plant because its leaves respond to touch as do those of the true sensitive plant, a mimosa. Senna is classified in the division Magnoliophyta , class Magnoliopsida, order Rosales, family Leguminosae.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

See more Encyclopedia articles on: Plants

Browse By Subject