Stems 1.5-5.5(-8) cm. Leaves 1-4 mm, apex narrowly to broadly acute to rounded-obtuse; margins weakly to strongly recurved in proximal half or sometimes nearly to the apex, generally smooth near the insertion, margins of leaf apex strongly papillose but without teeth; marginal laminal cells weakly papillose by projecting distal cell ends or smooth in proximal half of the leaf; median leaf cells with horned papillae on both surfaces; costal cells adaxially elongate (3-6:1), often smooth, clearly different from adjacent laminal cells. Specialized asexual reproduction occasional, by mullticellular ovoid to ellipsoidal gemmae borne on branched, rhizoid-like structures in the leaf axils. Sexual condition dioicous. Seta 9-20 mm. Capsule 1.2-1.6 mm, not strumose, smooth when dry. Spores 13-20(-25) µm.
Capsules mature late fall-early spring. Moist soil on banks, wet cliffs, near streams, calcareous or acid rock; low to high elevations (to 2300 m); Greenland; Alta., B.C., N.B., Nfld. and Labr., N.S., Nunavut, Ont., P.E.I., Que., Yukon; Alaska, Ariz., Calif., Colo., Idaho, Mich., Minn., Mont., N.J., N.C., Ohio, Oreg., Pa., Tenn., Utah, Wash., Wis.; Europe; Atlantic Islands (Iceland).