Deciduous shrub or small tree growing to 16 ft (5 m). Has smooth brown bark, oval to elliptical leaves, white flowers in late spring, and small round berries ripening from yellow to black.
Habitat & Cultivation
Alder buckthorn grows in Europe (except for the Mediterranean region and the extreme north), and in northeastern parts of the U.S. It prefers marshy woodland. The bark of trees at least 3–4 years old is collected in late spring and early summer, and is dried and stored for at least 1 year before use.
Alder buckthorn contains 3–7% anthraquinones (including frangulin and emodin), anthrones, anthranols, an alkaloid (armepavine), tannins and flavonoids. The anthrones and anthranols induce vomiting, but the severity of their effect lessens after long-term storage. The anthraquinones found in alder buckthorn and closely related species act on the wall of the colon, stimulating a bowel movement approximately 8–12 hours after ingestion.
Medicinal Actions & Uses
Alder buckthorn is a laxative and a cathartic, and is most commonly taken as a treatment for chronic constipation. Once dried and stored, it is significantly milder than senna (Cassia senna) or common buckthorn (R. catharticus) and may be safely used over the long term to treat constipation and to encourage the return of regular bowel movements.
Alder buckthorn is a particularly beneficial remedy if the muscles of the colon are weak, and if there is poor bile flow. The plant should not be used for constipation caused by excessive tension in the colon wall.
Cascara sagrada (R. purshiana), native to woodlands along the Pacific coast of North America, is used medicinally in much the same way as alder buckthorn. Common buckthorn (R. cartharticus), a European native, is today used mainly in veterinary medicine.
Use only dried bark that has been stored for at least a year, as the fresh bark is violently purgative. The berries may also be harmful if eaten.