Herbaceous perennials. Roots present. Stems unbranched or dichotomously branched. Leaves usually spirally arranged, less than 1.5 cm long, without ligule. Sporophylls may be modified and aggregated into strobili. Spores of one sort only. Sporangia borne singly in axil of sporophyll, more or less reniform, opening by transverse slit. Gametophyte minute, colourless or green, associated with symbiotic fungi.
4 genera, all represented in Australia.
The genera recognized here are those delineated by Ollgaard (1987, 1989) and to be used in the forthcoming Flora of Australia. Although the three genera previously included in Lycopodium are somewhat artificially separated in the key, they appear to represent three distinct lineages based on anatomical, microscopic and chemical criteria.