Plants in loose to rather dense pure tufts, dull olive green, becoming dark reddish brown with age. Stems 3--10 cm, arising from a short, erect tuberous rhizome, slender and thread-like, distantly bracteate and appearing almost leafless proximally, ± abruptly leafy distally. Leaves loosely imbricate, 4--6 mm, linear-lanceolate from a sheathing base, the sheath yellowish and nitid, clasping stem; limb reflexed at the shoulders, subtubulose, twisted and contorted when dry, widely spreading and almost plane when moist; costa slender, percurrent, smooth abaxially, ending in a short spine; margins of sheath entire proximally, not hyaline-margined, at shoulders cilia 1-seriate, 0.4--0.6 mm, cells distinctly papillose; no hinge tissue; margins of limb plane, serrations ending in a conical tooth cell, sometimes with 1--2 short cilia near the shoulders; lamina 2-stratose except for a narrow strip just within the margin and locally 1-stratose streaks and patches, adaxial layer of cells strongly bulging mamillose in indistinct longitudinal rows; lamellae 4--5(--9), restricted to the costa, 4--8(--10) cells high, serrations ending in a small toothed cell; sheath cells linear at margin, the median short-rectangular, 23--28 × 6--9 µm; abaxial laminal cells irregularly arranged, subquadrate, 6--10(--12) µm, walls evenly thickened and firm; abaxial costal cells sharply differentiated, narrowly elongate to linear, 25--33(--55) × 5--6 µm. Sexual condition dioicous; male plants like the female, male inflorescence inconspicuous, several to a shoot, separated by sectors with normal vegetative leaves, perigonial bracts with a broader sheath, but otherwise like the leaves; perichaetial leaves scarcely differentiated. Seta rather stout, 7--12 mm. Capsule yellowish brown, erect, 2.5--4 mm, widest at the mouth; exothecial cells short-rectangular, 40--62 × 26--30 µm, smaller and ± isodiametric below mouth, smooth; stomata superficial, confined to the tapering neck; operculum almost as large as urn, beak about 1 mm; peristome none; columella broadly flaring, extending to capsule rim. Calyptra cucullate.

Soil banks or soil over rock, exposed tree roots; B.C.; Alaska (including Aleutians), Wash.; Asia (Japan; Russia in Kamtschatka).