|See also sea buckthorn any of several thorny small-flowered shrubs of the genus Rhamnus, esp the Eurasian species R. cathartica, whose berries were formerly used as a purgative: family Rhamnaceae|
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any of about 100 species of shrubs or trees belonging to the genus Rhamnus, family Rhamnaceae, native to temperate areas in the Northern Hemisphere. The cascara buckthorn (R. purshiana) is the source of cascara sagrada, a cathartic drug.
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