A North American buckthorn (Frangula purshiana, syn. Rhamnus purshiana) whose bark is used as a laxative. / Dried coffee cherry fruit used in teas and other drinks.

plural of cascara

(pharmacology) A purgative made from the dried bark of an American buckthorn. / The tree from which cascara is obtained (Rhamnus purshiana), native to western North America.

The dried bark of a Honduran tree Picramnia antidesma once used to treat syphilis