Plants: in dense tufts, light to dark green, dark brown or sometimes nearly black, dull. Stems: 2–8 cm, densely tomentose with brown to orange rhizoids nearly to stem apex. Leaves: falcate-secund to erect-spreading, often at wide angles from stems, strongly crisped when dry, often with a few undulations in the distal half, (3–)5.5–6.5(–8.5) × 0.4–0.8 mm, concave below, keeled above, lanceolate, acute; margins entire below, serrulate above, incurved in the middle of the leaf; laminae 1-stratose or with 2-stratose regions in distal half of leaf, especially on margins, sometimes with entire laminae 2-stratose, rarely margins 3-stratose; costa percurrent or shortly excurrent, 1/6–1/4 the width of the leaves at base, very prominent and rounded on abaxial surface, smooth or slightly rough above on abaxial surface, abaxial ridges absent, shaped like a pair of tongs, with one row of guide cells, 2 well-developed and thick stereid bands extending to the apex, adaxial epidermal layer of cells not differentiated, the abaxial layer differentiated; cell walls between lamina cells strongly bulging; leaf cells smooth to papillose above on abaxial surface; alar cells 2-stratose, differentiated, sometimes extending to costa; proximal laminal cells elongate-rectangular, pitted or not pitted, (15–)31–46(–75) × (5–)7–9(–12) µm; distal laminal cells short, irregularly quadrate-rectangular, not pitted, (5–)7–14(–37) × (4–)8–9(–13) µm. Sexual: condition pseudomonoicous; dwarf males on stem rhizoids of female plants; interior perichaetial leaves abruptly short-acuminate, convolute-sheathing. Seta: 1.3–3.5 cm, solitary, yellowish to brown. Capsule: 2–4 mm, long-cylindric, arcuate, inclined to horizontal, not or slightly strumose, striate to furrowed when dry, yellowish brown to dark brown; operculum 1–2.5 mm. Spores: 14–30 µm. Phenology: Capsules mature summer.
Humus or soil over rock, rarely rotted wood, exposed to protected bluffs or cliffs, 70-3700 m. Greenland, Alta., B.C., Man., Nfld. and Labr. (Nfld.), N.W.T., Nunavut, Ont., Que., Yukon, Alaska, Colo., Mich., Mont., N.Mex., S.Dak., Europe, Asia.