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A genus of poisonous and rhamnaceous trees and shrubs commonly called buckthorn. The bark and fruit of its many species are commonly used as purgatives. The most common species are Rhamnus cathartica (purging buckthorn), Rhamnus frangula (alder buckthorn, a cathartic), and Rhamnus purshiana, the bark of which is the source of CASCARA and EMODIN. Karwinskia humboldtiana of the family Rhamnaceae, known also as tollidora, causes buckthorn polyneuropathy, an ascending paralysis resulting from the ingestion of Karwinskia fruit.

The bark of Rhamnus frangula (Frangula vulgaris), employed as a laxative or cathartic in doses of gr. 5-15 (0.3-1.0).

A bark with purgative and cathartic properties.

Bark of Rhamnus frangula, a species of buckthorn: purgative.

The genus Rhamnus.

Of the U. S. Ph., the bark of Rhamnus frangula.