Calamus (U. S. P.)—Sweet Flag.

Botanical name: 

Photo: Acorus calamus. Preparation: Fluid Extract of Calamus - Wine of Rhubarb

The rhizome of the Acorus Calamus, Linné.
Nat. Ord.—Aroideae.
COMMON NAMES: Sweet flag, Calamus.
ILLUSTRATIONS: Willdenow, Sp. Plants, II., 199; Woodville, Med. Bot., 248; Barton, Med. Bot., II, 63; Bentley and Trimen, Med. Plants, 279.

Botanical Source.—Calamus is an herbaceous, perennial, aromatic, flag-like plant, flourishing in wet situations. The leaves are long, radical, and sword-like, erect, bright green, but reddish or pink at the base, where they are ensheathing. The stalk is triangular, giving off from one side a spadix bearing thickly crowded, perfect greenish-yellow flowers.

History.—Calamus grows in muddy places, in swamps and meadows, along streams and the borders of lakes, in nearly all parts of India and Central Asia (from whence it has spread to other parts of the globe), Southern Siberia, Japan, China, Europe, and North America. In Ceylon and Burmah it is cultivated to some extent. Persian and East Indian calamus is said to be of better quality than that of other parts of the world. In America it blooms from April to July. The rhizome should be gathered in early spring or in October and November, freed from dirt and its bitter rootlets, and dried quickly in a gently warmed room. The leaves also possess the aromatic properties of the rhizome, but to a lesser degree, and are not employed as a medicine. This drug and the calamus of Scripture are probably identical. Sweet flag has long been a popular remedy in India, where large quantities of it are yearly sold in the bazaars. According to Ainslie (1813), it is there considered so valuable in the bowel disorders of children that a penalty is incurred by any pharmacist who will not open his shop in the night to sell it when called upon to do so (Pharmacographia). The Hindus regard it as an emetic in large, and stimulant, tonic, an carminative in small doses, and employ it in stimulant doses in paralysis and other nervous disorders. The Mahometans use it internally in calculous troubles, and advise its use for teething children to bite upon. An infusion is considered in Ceylon as an efficient anthelmintic for children (Dr. Ondaatji, Col. Surg. of Ceylon). Evers found the decoction useful in diarrhoea and dysentery, and infantile bronchitis, and often used it personally for cold in the chest. Watts states that it is useful for distressing cough (Dymock, Mat. Med. Western India).

Description.—The rhizome, or part employed, is subspherical, creeping, fleshy, thick, and rather spongy, and gives off numerous rootlets. It is often several feet in length, and shows upon its upper surface triangular leaf-scars, which are occasionally apparently hairy (when dried), and on the lower surface may be seen several zigzag or wavy lines composed of circular dots, indicating where the rootlets were attached. The rhizome is occasionally wrinkled longitudinally, and has a brownish-yellow color (pinkish shortly after being peeled). It has a peculiarly agreeable, aromatic odor, and an aromatic, bitterish, pungent taste. The dried roots of commerce are from 3 to 6 inches long, light-brown or fawn colored, of a whitish or slightly roseate hue internally, corrugated outside, and break with a spongy or cork-like fracture. It has the peculiar warm, pungent taste possessed by the green rhizome. It loses its strength with age, and is liable to destruction by worms. Water or alcohol takes up its medicinal virtues. To preserve it, it should not be peeled. The U. S. P. describes it as follows:

"In sections of various lengths, unpeeled, about 2 Cm. (3/4 inch) broad, subcylindrical, longitudinally wrinkled; on the upper surface marked with leaf-scars forming triangles, and on the lower surface with the circular scars of the rootlets in wavy lines; externally reddish-brown, somewhat annulate from remnants of leaf-sheaths; internally whitish, of a spongy texture, breaking with a short, corky fracture,; showing numerous oil cells and scattered wood bundles, the latter crowded within the subcircular endoderm. It has an aromatic odor, and a strongly bitter taste "—(U. S. P.).

Chemical Composition.—Trommsdorff found it to contain essential oil, resin, extractive with chloride of potassium, gum with phosphate of potassium, starchy matter, woody fiber, and water. The oil is lighter than water, and is pale yellow, very odorous and pungent. Kurbatow (1873) found this oil to contain a hydrocarbon (C10H16), which, with hydrochloric acid, formed a crystalline compound, and another hydrocarbon refusing to combine with this acid (Pharmacographia). Faust (1867) obtained a bitter glucosid, of a brownish color, and of a semi-fluid consistence, which he named acorin (C36H60O6). It contains no nitrogen when purified, is insoluble in water and benzol, but dissolves in alcohol, methylic alcohol, chloroform, and ether. Flückiger (Pharmacographia), by precipitating a decoction with tannin, and treating the precipitate with litharge, and exhausting the residue with chloroform, obtained a minute quantity of a very bitter, crystalline solid. Thoms (1886) thought to have obtained a crystalline alkaloid, calamine, which, however, in 1888 he declared to be trimethylamine. This result is supported by the observation of Kunz (1888) who found choline to exist in calamus root.

Action, Medical Uses, and Dosage.—The root is carminative, slightly tonic, and excitant, and forms a useful adjunct to other tonics and stimulants. It may be used in cases of flatulent colic, atonic dyspepsia, feebleness of the digestive organs, and to aid the action of cinchona or quinine in intermittents. It forms an excellent substitute, in syrup, for Godfrey's cordial. In flatulent colic of infants it is best combined with magnesia. Externally, it is a valuable application to indolent ulcers, and to keep up the discharges from blistered surfaces and issues. Dose of the infusion made by scalding 4 drachms of the root, coarsely bruised, in 8 fluid ounces of water, from 4 to 6 fluid ounces; of the powdered root, 20 to 40 grains; a tincture may be prepared from 1 part of the root and 5 parts of alcohol. Dose, from 5 to 30 minims.

King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.