Acorus Calamus. Calamus.

Nat. Ord. — Araceae. Acoraceae. Sex. Syst. — Hexandria Monogynia.

The Rhizoma.

Description. — Calamus, sometimes called Sweet Flag, has a perennial, horizontal, jointed, and compressed root or rhizome, from six to twelve lines thick, and several feet in length, and which sends off numerous, long, round, and slender radicles, of a whitish or yellowish color, also bunches of brown fibers from its joints, which resemble coarse hair ; internally the root is white and spongy, externally whitish with a tinge of green, and the joints are from half an inch to an inch in length, and are variously shaded with different tints of white and red. The leaves are radical, sheathing at the base, long, sword-shaped, smooth, green above, but of a reddish color below, variegated with green and white. The scape ox flower-stem resembles the leaves, is usually longer, and from one side near its middle it sends out a naked, solitary, oblique, and cylindrical spadix, tapering at each end, about two inches in length, and closely covered with small, pale or yellowish-green flowers, which have no scent except when bruised. These are without calyx, and have six equal truncated scales, inclosing six stamens, having thick filaments and bilobate anthers. The ovary is sessile, three-celled, with a pointed stigma. The capsule is several-seeded.

History. — Calamus is found in most parts of the world, growing on the borders of small streams, ponds, wet meadows, swamps, etc., and flowering in May and June. The part used is the root or rhizome. It should be collected late in the autumn, or in the spring, washed, deprived of its fibers, and dried with a moderate heat. The dried roots of the shops are of various lengths, somewhat flattened, of a yellowish-brown color externally and wrinkled, internally whitish, or yellowish-white, and of light and spongy texture. Water or alcohol take up its virtues. It has a strong and fragrant odor, and a warm bitterish aromatic taste. It contains volatile oil, resin, extractive, etc. ; the oil is lighter than water, and is pale-yellow, very odorous and pungent.

Properties and Uses. — A stimulating tonic, and aromatic. Useful in flatulent colic, dyspepsia, atonic conditions of the stomach, various affections of the alimentary canal, and as an adjuvant to quinia and bark in, intermittents. It forms an excellent substitute in syrup for Godfrey's Cordial. Externally, it is a valuable application to indolent ulcers, and to keep up the discharge from blistered surfaces and issues. Dose of the infusion, made by scalding an ounce of the root in a pint of water, from four to six fluid ounces ; of the root, from a scruple to a drachm. In flatulent colic of infants, it is best combined with magnesia.

Of. Prep. — Decoctum Acorus; Infus. Acorus.

The American Eclectic Dispensatory, 1854, was written by John King, M. D.