The dried bark of the rhizome of Ru'bus villo'sus Aiton, Rubus Nigrobaccus, Bailey, and Rubus cuneifolius Pursh.
DESCRIPTION OF DRUG.—In thin, tough, pliable bands 1 to 2 mm. (1/25 to 1/12 in.) thick, having a blackish-gray outer surface, longitudinally wrinkled, and a pale brown inner. surface; bast layers tangential, the fibers easily removed. Odorless; taste astringent and somewhat bitter. The root of Rubus canadensis Linné (dewberry) very closely resembles that of blackberry in medical properties.
Powder.—Light brown. Characteristic elements: Parenchyma of cortex, thin walled, with starch, spherical (3 to 7 µ in diam.), thick, porous, elongated; bast fibers, walls of medium thickness, with some starch; wood fibers, ducts and tracheids, numerous with simple pores; cork considerable (20 to 30 µ in diam.); calcium oxalate crystals, aggregate (25 to 30 µ in diam.).
CONSTITUENTS.—The virtues of the bark depend chiefly upon the tannin present, about 10 to 15 per cent.
ACTION AND USES.—Tonic and astringent. From a popular domestic remedy it has come into extensive use in the treatment of diarrhea, dysentery, and relaxed conditions of the bowels generally. Dose: 15 to 30 gr. (1 to 2 Gm.).
PREPARATIONS: Fluidextractum Rubi, Syrupus Rubi, N.F.
RUBI FRUCTUS, N.F.—Includes two varieties of ripe fruits: Nigrobaccus and Villosus. A Syrup is recognized in the N.F.
