Lycopodium clavatum is a spore-bearing vascular plant, growing mainly prostrate along the ground with stems up to 1 m (39 in) long; the stems are much branched, and densely clothed with small, spirally arranged microphyll leaves.

The stems superficially resemble small seedlings of coniferous trees, though it is not related to these.

In the UK it is one of 101 species named as a high priority for conservation by the wild plant charity Plantlife.

The dried spores of this moss are explosive if present at high density in air.

[14] Bioactive secondary metabolites in clubmosses include triterpenoids with acetylcholinesterase inhibitor activity isolated from this species.