LYCOPODIUM, in botany, a genus of the cryptogamia musci class. The anthera is double-valved, and sessile; the calyptra is wanting. There are 24 species, of which six are natives of Britain, viz. the clavatum, or common club-moss; the inundatum, or marsh club-moss; the annotinum, or Welsh club-moss; the alpinum, or mountain-club-moss; the selago, or fir club-moss; and the selaginoides, or prickly club-moss.