Was used in an exhibit for the International Congress of the History of Medicine in Montreal; used by the North American Indians; note: crude drugs were used in Canada quite extensively until around the 1920s; habitat for Rhamnus purshiana: Northwest Pacific Coast; parts used: bark; uses: popular laxative; official preparation; U.S.P. 1890-present, marketed as Danthron, Sennapod, Senekot, Peri-Colase.