Synonyms.—Acori Calami Rhizoma; Calamus Rhizome; Calamus Root; Sweet Flag Root.
Calamus is obtained from the sweet flag, Acorus Calamus, Linn. (N.O. Aroideae), a plant indigenous to Eastern Europe and Central Asia, but widely diffused by cultivation, and growing wild in England. It is official in the U.S.P. The rhizome is collected in the autumn, trimmed, sometimes scraped or peeled, cut into pieces several centimetres in length, and dried. The drug occurs in sub-cylindrical pieces, usually from 5 to 15 centimetres in length, and 12 to 25 millimetres in diameter. The unpeeled rhizomes are covered with a thin, brownish epidermis, and are deeply wrinkled longitudinally. The upper surface bears large triangular encircling leaf-scars, while the under surface exhibits an irregular zigzag line of small, rounded root-sears; the surface of the peeled rhizome is paler and slightly fibrous, the scars being less conspicuous. The drug breaks with a short fracture, and is nearly white and spongy internally. The transverse section exhibits a large stele and thick cortex. Calamus has a sweet aromatic odour, and a bitter, pungent taste.
Constituents.—The chief constituent is a bitter aromatic volatile oil, present to the extent of 1.5 to 3.5 per cent. The drug also contains starch, tannin, and a bitter amorphous principle, acorin, which yields acoretin by oxidation. The rhizome is said to contain certain alkaloidal substances, but this statement requires confirmation. The chief aromatic constituent of the volatile oil is asaryl alcohol; eugenol, asarone, and other bodies have also been found in it.
Action and Uses.—Calamus has the action of an aromatic bitter. On account of the volatile oil which is present it also acts as a carminative, removing the discomfort caused by flatulence and checking the growth of the bacteria which give rise to it. It is used to increase the appetite and benefit digestion. It may be given in the form of fluidextract, infusion or tincture. The essential oil is used as an addition to inhalations.
Dose.—1 to 4 grammes (15 to (60 grains).
- Fluidextractum Calami, U.S.P.—FLUIDEXTRACT OF CALAMUS.
- Calamus, in No. 40 powder, 100. alcohol (95 per cent.), mixed with one-third its volume of water, to 100. Average dose.—1 mil (15 minims).
- Infusum Calami, B.P.C.—INFUSION OF CALAMUS. 1 to 10.
- Dose.—15 to 30 mils (½ to 1 fluid ounce).
- Tinctura Calami, B.P.C.—TINCTURE OF CALAMUS, 1 in 5.
- Dose.—2 to 4 mils (½ to 1 fluid drachm).