Bryol. Univ. 1: 400. 1826,.
Plants soft, in small, loose tufts, light to very dark green. Stems 1–2.5 cm. Branch leaves strongly crisped and curled when dry, ovate-lanceolate, abruptly subulate, entire or sometimes serrated above, 3–6 mm, subtubulose above, strongly sheathing at base, margins plane; costa mostly percurrent; laminal cells mostly 1-stratose, 2-stratose only at margins; distal laminal quadrate to short-rectangular, incrassate; basal laminal cells elongate, rectangular, incrassate, alar cells not differentiated. Seta (8–)10–15(–21) mm. Capsule pale yellow-brown, furrowed when dry, 0.8–2 mm, peristome bright red. Spores 14–20(–30) µm.
Phenology: Capsules mature late spring–early summer.
Habitat: Rotten logs along streams or in flooded areas, less commonly on soil, humus, rock or bark at the base of coniferous trees (e.g., Thuja)
Greenland, Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.W.T., N.S., Nunavut, Ont., P.E.I., Que., Sask., Yukon, Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo., Europe, Asia.
A common epixylic species, Oncophorus wahlenbergii may be confused with the more saxicolous O. virens, which has keeled, revolute, non-sheathing leaves that gradually narrow to the subula. A compact, densely tufted arctic-alpine form has been treated as var. compactus and is often found on dry soil.