Plants terrestrial or on rocks, small to medium-sized. Stem erect or ascending, 3-32 cm, dichotomously branched, upper portion of stem and branchlets often with bulbils. Leaves linear or lanceolate, often papery, margin entire or serrate. Strobili homomorphic with sterile branches or branchlets. Sporophylls homomorphic with trophophylls but slightly smaller. Sporangia in axils of sporophylls of upper portion of stem or branchlets, reniform, dehiscent in 2 valves. Spore sides at equator concave with truncate angles.

About 55 species: temperate and arctic zones; 27 species (18 endemic) in two sections in China.