Lycopodium Linnaeus (1753: 1100

Lycopodium Linnaeus (1753: 1100). Type: Lycopodium clavatum L. sensu stricto

Sporophytes terrestrial, anisotomously branched, with elongate, indeterminate, creeping, or scandent, plectostelic main stems (rhizomes), which, in a dorsolateral position, give rise to usually determinate, ascending to erect, or spreading, repeatedly dorsolaterally branched, branchlet systems. Roots emerging directly along the underside of main stems, with plectostelic main roots. Branchlet leaves uniform terminating in a colorless hair tip or membranous apex. Strobili erect, simple or forked, borne on simple or forked peduncles or sessile. Sporophylls subpeltate with a thin basal decurrent wing, with a basal mucilage-bearing cavity. Sporangia attached to the sporophyll base, reniform, with a short thick stalk, isovalvate, their epidermal cells with thin, lignified, sinuate side walls, with numerous small in-and evaginations. Spores reticulate on all faces.

The generic description includes the neotropical representatives of the genus, which has one species (two subspecies) in Panamá, and two species in South America. Fifteen species are recognized worldwide. The genus occurs in all continents except Australia. Lycopodium clavatum is virtually cosmopolitan and quite variable, as indicated by the large number of names referred to this species below.