Rhamnus purshiana

Rhamnus purshiana, commonly known as cascara sagrada (Spanish for "sacred bark"), is a plant whose bark is used medicinally as a laxative. This buckthorn species is cultivated in North America and Kenya. The laxative effect is attributed to compounds called anthraquinones. Buckthorn is a genus of shrubs and trees native to the Northern Hemisphere. While Rhamnus purshiana is known for its medicinal bark, other buckthorn species have different uses, such as providing dye or serving as ornamentals. Some introduced buckthorn species have become invasive pests.123