Ge'um riva'le, Purple (Water) Avens. -- The rhizome, U.S.P. 1820-1870; N. America. Perennial plant .3-.6 M. (1-2 degrees) high, stem purple; leaves 3-foliate or 3-lobed; flowers purplish-orange. Rhizome 5-7.5 Cm. (2-3') long, 6 Mm. (1/4') thick, tuberculate, wrinkled, brownish-red; bark thin, wood-wedges white, pith large; aromatic, astringent, bitter; contains volatile oil, tannin, bitter principle. Astringent, tonic; diarrhea, hemorrhage, leucorrhea, phthisis, scrofula, rheumatism, intermittents, dyspepsia, menstrual derangements; decoction, infusion, tincture. Dose, gr. 15-30 (1-2 Gm.).