Lycopodium (Gr.Lycopodium 1000263 a wolf, andLycopodium 1000264 a foot, a name of obscure application), the botanical name for a genus of cryptogamous plants popularly known as club mosses; this with a few other genera make up the family lycopodiacece, in which some botanists include two singular aquatic genera: pillwort (pilula-ria), and quillwort (isoetes). The lycopodiums are low perennials having something of the habit of the true mosses; their evergreen, one-nerved leaves are crowded upon the stems in from four to several ranks; the rather large spore cases (sporangia) are usually kidney-shaped, and placed either in the axils of the upper stem leaves, or at the base of broad bract-like leaves which are collected into a distinct spike; each spore case opens by means of a slit in two valves, and emits the spores in the form of a copious sulphur-colored powder. The germination is believed to be through the agency of a prothallus, as in ferns, but this is not well determined. The club mosses are found in all parts of the world, some growing in high arctic latitudes, while others, and the finest species, occur in the tropics.

East of the Mississippi there are nine species, with some well marked varieties; one of the best known of these is the one chosen for illustration, the common club moss, L. clavatum, which is widely distributed, and is found also in Europe and northern Asia. It has a strong creeping stem 1 to 2 ft. long, from which arise ascending, forked branches, 1 to 3 in. long; the whole plant is covered with small mosslike leaves, which have fine bristle-like points; the spikes are usually two or three together, 1 to 1 1/2 in. long; the bracteal leaves about half as large as the stem leaves. The plant had formerly a reputation as a remedy in diseases of the bladder, and is now of considerable importance on account of its spores, which, are Known in commerce as lycopodium; when the spore cases are well formed, the plant is collected and dried, and the spores can then readily be separated by shaking and sifting; when examined by a microscope, the spores appear as spheroids upon a portion of the surface of which are three faces uniting to form a three-sided pyramid.

In the mass the spores appear as a very mobile powder, which when rubbed between the fingers has a remarkably smooth feel; sprinkled upon the surface of water, lycopodium floats, and the hand may be dipped in water thus covered without its being moistened. In pharmacy lycopodium is used to prevent the adhesion of pills, and in medicine it is sometimes applied to excoriated surfaces; it is used in pyrotechny, but its chief consumption is for the production of artificial lightning for theatrical representations; when diffused the powder is very inflammable, and a cloud of it shaken into the air near a flame burns with a rapid flash. Some is collected in this country, but the greater quantity is imported from Europe. The most showy of our club mosses is L. dendroideam, its tree-like habit being recognized in its botanical name as well as in its popular one of ground pine; in this the stems arise from a subterranean, creeping root stock, and are from 6 to 9 in. high and branched above, the crowded fan-like branches spreading and clothed with very small leaves, giving the plant much the appearance of a miniature coniferous tree; it is found in moist woods, and in some localities is quite abundant.

The delicate character of the plant and its fine dark green color make it valued by florists for use in constructing bouquets and floral decorations; it is an article of commerce under the name of bouquet-green, and many barrels are sent from the southern counties of New Jersey to New York and thence to all parts of the country; kept in a cool cellar where it will not dry up, it preserves its freshness for several months. Another species, L. complanatum, has very extensively creeping stems, several feet in length, along which arise numerous fan-like branches, which are densely clothed with small leaves. This species is largely used to make wreaths and other Christmas decorations; just before the holidays immense quantities of this are sold in New York and other cities; the steins are tied together to form continuous "ropes," as the dealers call them, and are sold by the yard; the preceding species is also in great demand for Christmas green. Some of our species are only found upon high mountains or far northward, while others inhabit swamps and bogs; but the three above mentioned are the only ones that have any interest except to botanists. - The delicate plants cultivated in greenhouses for the beauty of their foliage, though generally called lycopodiums, belong to a related genus, selaginella, which differs from ly-copodium in having spore cases of two kinds, one two-valved, containing innumerable minute spores, and the other three- or four-valved, with three or four large spores; three species of this genus are found wild in the northern states, but they are greatly inferior in beauty to the exotics; one of the commonest of these is S. Kraussiana (lycopodium denticulatam of the florists), which is a very quick-growing species, well adapted to a Wardian case, and when the air is not too dry will sometimes flourish in a hanging basket.

A dozen or more other species are to be found in collections of plants. An interesting species is found in southern California and northern Mexico, 8. lepidophylla; it consists of a tuft of flattened branching stems clothed with minute leaves, and has much the aspect of a fern. In the arid climate in which the plant is found clinging to the crevices of rocks, the stems are for the greater part of the year curled up to form a nest-like ball, and show only their brown under surfaces; when the rainy season comes, the dry stems uncurl, and the plants then appear as beautiful rosettes of a brilliant green. When quite dead the plants retain this property of expanding when moistened, and are frequently sold by street venders as " resurrection plants." - The lepidodendrons, sigillarias, and other plants of the coal formation were enormous forms of lycopodiaceae.

Common Club Moss (Lycopodium clavatum)

Common Club Moss (Lycopodium clavatum).