This section is from the book "A Text Book Of Materia Medica, Being An Account Of The More Important Crude Drugs Of Vegetable And Animal Origin", by Henry G. Greenish. Also available from Amazon: A Text Book of Materia Medica : Being an Account of the More Important Crude Drugs of Vegetable and Animal Origin.
Lycopodium consists of the spores of the common clubmoss, Lycopodium clavatum, Linne (N.O. Lycopodiaceoe), and probably other species. The clubmoss, with its long creeping stems and ascending branches covered with narrow moss-like leaves, is distributed over Great Britain and Europe generally. It produces fruiting branches covered with small scaly leaves and resembling a slender elongated cone. On the upper surface of these leaves (sporophylls) near the base are small receptacles (sporangia) filled with minute spores. These spores form the drug; they are collected by shaking, the fruiting branches over a cloth in which the lycopodium collects as a fine yellow powder which is freed from extraneous matter by passing it through a fine sieve and is then packed in sacks, which are usually covered with matting. It is collected chiefly in Russia.
Lycopodium appears as a pale yellow, fine, very mobile powder that floats when thrown on to the surface of water. Blown into a flame it burns instantly with a brilliant flash, but when incinerated in a crucible it is slowly consumed, leaving only about 4 per cent. of ash.
Examined under a microscope lycopodium is seen to be composed entirely of minute spores, each of which is about 25μ in diameter and has the shape of a triangular pyramid with a convex base. The entire surface of the spore is covered by a delicate network of projecting ridges. When crushed the spores burst and a drop of yellowish oil exudes from each. These characters are so well marked that sophistication is readily detected.
The spores contain about half their weight of fixed oil, which, however, does not make itself evident until the cellular membrane in which it is enclosed is either broken or destroyed. The oil consists principally of lycopodium-oleic acid (80 per cent.) and myristic acid (about 2 per cent.) combined with glycerin. Lycopodium-oleic acid resembles ordinary oleic acid but is not identical with it. Phytosterin, sugar, and traces of an alkaloid are also present in the drug. Pure lycopodium yields about 1 to 1.5 per cent. of ash.
FIG. 225. - Lycopodium. A, portion of Lycopodium clavatum, natural size: a, foliage leaf; 6, sporophyll with sporangium, magnified; c, d, e, spores, highly magnified. B, Prothallium of an allied species. (Luerssen).
Lycopodium is sometimes used as a dusting powder for excoriated surfaces and for preventing the mutual adhesion of pills.
Lycopodium is frequently adulterated, the following substances, all of which are easily detected by microscopical examination, having been found: - potato starch, maize starch slightly roasted and coloured, sulphur, powdered colophony, powdered amber, dextrin, powdered boxwood, powdered talc, and pollen of various kinds, especially that of coniferous trees, which has been actually sold (in Austria) under the name of Lycopodium hungaricum. Pine pollen consists of ovoid grains bearing an enlargement on each side. The drug should not yield more than 4 per cent. of ash (absence of mineral matter). Sulphur may be detected by its solubility in carbon disulphide.