Plants in soft, readily disintegrating cushions, yellow-green to brownish, occasionally light green, blackish to red-brown inside. Stems 1--4 cm, small central strand present. Stem leaves contorted when dry, patent when moist, lanceolate, 1.5--2 × 0.3-0.5 mm, keeled, margins slightly recurved below, plane above, awns very short and smooth, occasionally absent, costa weak below, projecting on dorsal side; distal laminal cells 1-stratose; medial laminal cells rectangular, extremely sinuouse, thick-walled; basal juxtacostal laminal cells linear, extremely sinuose, thick-walled; basal marginal laminal cells quadrate, hyaline with straight walls. Gemmae brown multicellular gemmae present on the dorsal side of distal leaves. Sexual condition dioicous. Seta slightly curved, straight when dry, 3--5 mm. Capsule sporadically present, exserted, ovoid, brown, smooth, striate when dry and empty, exothecial cells thin-walled, annulus present, operculum rostrate, peristome teeth yellowish, short, split in distal part, weakly papillose. Calyptra mitrate.

Damp, frequently vertical faces of acidic rock; 200--4000 m; Greenland; Alta., B.C., Labrador, Nfld., N.W.T., Ont., Que., Yukon; Alaska, Ariz., Calif., Colo., Idaho, Mont., Nev., Ore., Wash.; Mexico; north Africa; Eurasia; Pacific Islands (Hawaii).

Grimmia torquata is a montane-alpine species with a preference for shaded habitats. It grows in hemispherical cushions on steep, damp rock walls. Favorite substrates are granite, gneiss, quartzite and schists. Its distribution area reaches from near sea level in the Arctic up to above 4000 m on Mexican and Hawaiian volcanoes. The species is easily recognized by its yellow-brown cushions with, when dry, contorted leaves, and brown gemmae, which are borne at the base of older leaves. In densely shaded habitats, the cushions are light-green; on exposed rock, they are usually brown. Although the species has a wide distribution, it is seldom present in quantity, usually growing in a small number of cushions in one habitat. Sporophytes are very rare worldwide and have not been found in eastern North America (H. A. Crum and L. E. Anderson 1981).