59. Convallaria.—(C. Flores and C. Radix, N. F.). Lily of the Valley.
The dried rhizome and roots and dried inflorescence of Convalla'ria majal'is Linné.
BOTANICAL CHARACTERISTICS.—A low, perennial, glabrous herb with slender, running root-stocks. Leaves 2, oblong, bright green, and shining. Scape bearing a one-sided raceme of white, bell-shaped flowers. Fruit a few-seeded red berry.
HABITAT.—North America, Europe, and Northern Asia.
DESCRIPTION OF "ROOT."—In pieces from 50 to 75 mm. (2 to 3 in.) long, and about 3 mm. (⅛ in.) thick, the upper end gnarled and wrinkled, and with the remnants of the scape and petioles attached, tapering at the small end; annulate nodes beset with a circle of eight or ten long, branching, gray rootlets; externally white, fracture white, tough, and fibrous. Odor distinct; taste sweetish, somewhat bitter and acrid. C. Flores—see N.F.
CONSTITUENTS.—Two glucosides, convallarin, C34H62O11 (the emetocathartic principle), acrid prisms, scarcely soluble in, but foaming when shaken with water; and convallamarin, C23H44O12, the cardiac acting principle, a sweetish, afterward bitter, crystalline powder.
Preparation of Convallamarin.—The estimation of the value of the drug is based upon the separation of this constituent. The drug is extracted with alcohol, the tincture treated with subacetate of lead, and filtered; excess of lead removed by careful addition of H2SO4; filter, distil off alcohol, add water, neutralize carefully with Na2CO3, add solution of tannin. The precipitate of tannin compound is dissolved in 60 per cent. of alcohol, decolorized with animal charcoal, decomposed with zinc oxide. The filtrate is then evaporated to dryness.
ACTION AND USES.—Convallaria was introduced as a safer cardiac tonic than digitalis. Its absence of cumulative action was pointed out by therapeutists. "It does not disturb the stomach or cerebro-spinal functions if preparations free from convallarin are used." It is one of the most active diuretics, especially in cardiac dropsies. Dose: 5 to 30 gr. (0.3 to 2 Gm.); of convallamarin ½ to 2 gr. (0.0324 to 0.13 Gm.).