Plants to 0.3 cm. Stem leaves flexuose-crisped and loosely appressed when dry, lanceolate, 1--2.2 mm, leaf base ovate, narrowly obtuse; margin reflexed, distal laminal cells 8--12 µm wide, with 1--2 large conic or forked papillae; basal laminal cells linear, grading to quadrate at margin, very thick-walled. Sexual condition autoicous. Seta 1.5--3 mm. Capsule ovate-oblong when mature, oblong to oblong-cylindric when old, 1.2--1.7 mm, strongly 8-ribbed for 3/4 length; stomates numerous in neck; peristome double; endostome segments 8, smooth; exostome teeth 8, incurved, smooth. Calyptra conic, very hairy. Spores 16--20 µm.

Acidic rock in montane and subarctic areas; 0--2000 m; Greenland; Alta., B.C., Lab., Man., Nfld., Nun., N.W.T., N.S. Ont., Que.; Alaska; n Europe; Asia.

This is a Canadian shield species in eastern North America, which has a range from the northern shore of Lake Huron and Lake Superior north to Hudson Bay and Baffin Island westward across the sub-Arctic of the Northwest Territories and southward in the Canadian Rockies to Alberta and southern British Columbia. This rock-growing species has strongly papillose, thick-walled distal leaf cells and stiffly flexuous leaves. Ulota hutchinsiae is more southern and has less papillose distal leaf cells and straight leaves. As with most other species of the genus, U. curvifolia has a rich chestnut brown coloration that helps indicate its identity in the field.