(Sweet Flag.)

Origin. - The unpeeled, dried rhizome of Acorus Calamus L., a plant indigenous in North America, Europe, and Western Asia, growing in swamps and along the shores of streams and ponds.

Description and Properties. - Calamus is found in subcylindrical sections of various lengths, about 1 inch (2 Cm.) broad, externally reddish-brown, internally whitish, of a spongy texture, breaking with a short, corky fracture, showing numerous oil-cells and scattered wood-bundles. It has a strong aromatic, fragrant odor and a warm, peculiar, bitterish taste. Calamus contains from 1 to 2 per cent. of volatile oil possessing the odor and taste of calamus, a glycosid (acorin) in the form of a bitter, yellow syrupy liquid, besides calamine, choline, resin, starch, and mucilage.

Dose. - 15-60 grains (1.0-4.0 Gm.) [15 grains (1 Gm.), U. S. P.].

Official Preparation

Fluidextractum Calami - Fluidextracti Calami - Fluidextract of Calamus. - Dose, 15-60 minims (1.0-4.0 Cc.) [30 minims (2.0 Cc.), U. S. P.].

Physiological Action and Therapeutics. - The action of calamus is similar to that of anise, but is more tonic than the latter. Large doses of the volatile oil produce tetanic convulsions.

It is used for the same purposes as anise, but probably possesses more stomachic and carminative properties.