Sepals: margins bristly-ciliate, abaxial surface hairy, sometimes stipitate-glandular. 2n = 26, 39, 48, 52. Flowering spring-summer. Arctic and alpine tundra, mountain ledges, rock crevices, calcareous gravel, raised beach ridges; 0-4000 m; Greenland; Alta., B.C., Man., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., Que., Yukon; Alaska, Colo., Idaho, Mont., N.Y., Oreg., Vt., Wash., Wyo.; Eurasia.