Ru'bia tincto'rum, Madder. -- The root, U.S.P. 1820-1870; S. Europe, Asia. Perennial herb, square stem, covered with short prickles by which it climbs; leaves elliptical, 7.5 Cm. (3') long; flowers yellow; root creeping, 5 Mm. (1/5') thick, reddish, sweetish, bitter, acrid, astringent taste; contains rubian (yellow), alizarin (orange-red), ruberythrin (yellow needles, blood-red with alkalies), purpurin. Used as tonic, diuretic, emmenagogue; dropsy amenorrhea, rachitis, dyeing. Dose, gr. 15-60 (1-4 Gm.).