Lycopodium.
Lycopodium consists of the spores of the common club moss, Lycopodium clavatum, Linn. (N.O. Lycopodiaceae), and other species of Lycopodium. It is official in the U.S.P. This club moss is a creeping plant indigenous to Europe, Asia, and North America, but the drug is collected chiefly in Russia. The plant produces fruiting branches, usually in pairs, resembling slender elongated cones. These bear sporophylls, at the base of each of which is a reniform sporangium enclosing a number of minute spores. When ripe, the sporangium opens, and the spores escape. The drug is obtained in July and August by beating and shaking the plants, and sifting the yellowish powder thus obtained. Lycopodium occurs as a pale yellow, very mobile, odourless, tasteless powder, which floats upon the surface of water without being wetted. It consists entirely of minute spores, having the shape of a triangular pyramid with a convex base. Each spore is minutely reticulated, and yields when crushed a drop of oil. Lycopodium yields, when pure, from 1 to 2 per cent. of ash. The drug is often adulterated, but its appearance under the microscope is so characteristic that sophistication can easily be detected. Among the substances chiefly employed as adulterants are starch, pine pollen, and powdered resin (colophony, amber, etc.). Powdered wood and bark, sulphur, and various other substances have also been detected. Lycopodium is best prepared for microscopical examination by moistening with alcohol, and immediately adding water or diluted glycerin. A little should also be mounted in fixed oil or liquid paraffin, and other media for comparison. Lycopodium Hungaricum is pine pollen collected in Hungary; the grains of which it consists are ovoid, and bear an enlargement at each extremity.
Constituents.—Lycopodium contains about 50 per cent. of fixed oil, which consists chiefly of lycopodium-oleic acid with a little, glyceryl myristate. The oil can be obtained by triturating the lycopodium with fine sand or pumice stone, and extracting with ether. Other constituents are sugar, traces of alkaloidal matter, and a phytosterol.
Uses.—Lycopodium is employed in dispensing as a covering for pills. It does not attract moisture and affords some protection to pills composed of hygroscopic substances. It is used as an inert dusting powder for the skin, to soothe inflamed surfaces and prevent friction. On account of its lightness it is a convenient diluent for insufflations of boric acid, tannin, etc., for the throat, nose, and ear; it is also employed as the basis of snuffs containing menthol, camphor, cocaine, etc., for use in nasal catarrh. A tincture of lycopodium is prepared, and has been prescribed for incontinence of urine and to allay spasm and irritation of the bladder.
PREPARATION.
- Tinctura Lycopodii, B.P.C.—TINCTURE OF LYCOPODIUM. 1 in 10.
- Dose.—1 to 4 mils (15 to 60 minims).
