Lycopodium (from Greek lukos, wolf and podion, diminutive of pous, foot) is a genus of clubmosses, also known as ground pines or creeping cedar,[1] in the family Lycopodiaceae, a family of fern-allies (see Pteridophyta). They are flowerless, vascular, terrestrial or epiphytic plants, with widely branched, erect, prostrate or creeping stems, with small, simple, needle-like or scale-like leaves that cover the stem and branches thickly. The leaves contain a single, unbranched vascular strand and are microphylls by definition. The kidney-shaped or reniform spore-cases (sporangia) contain spores of one kind only (isosporous, homosporous) and are borne on the upper surface of the leaf blade of specialized leaves (sporophylls) arranged in a cone-like strobilus at the end of upright stems. The club-shaped appearance of these fertile stems gives the clubmosses their common name.
Lycopods reproduce asexually by spores. The plant has an underground sexual phase that produces gametes, and this alternates in the lifecycle with the spore-producing plant. The prothallium developed from the spore is a subterranean mass of tissue of considerable size and bears both the male and female organs (antheridia and archegoniae). However, they are more commonly distributed vegetatively through above- or below-ground rhizomes.
About 950 species occur,[citation needed] with 37 species widely distributed in temperate and tropical climates, though they are confined to mountains in the tropics.
The genera Diphasiastrum, Lycopodiella, and Huperzia were once included within this genus, but are now recognized as being distinct. Some workers also segregate several more genera, including Dendrolycopodium for L. obscurum and related species, and Spinulum for L. annotinum and related species.
The spores of Lycopodium and Diphasiastrum species are harvested and are sold as lycopodium powder.
