Cells of the mid-limb lamina (6--)7--10(--12) µm wide (mean 8.5 µm); cells of distal part of leaf sheath non-papillose on abaxial surface (rarely papillose in non–North American specimens). Calyptra not persistent on seta.

Often with sporophytes. Most often in mesic, calcareous, open or well-vegetated arctic-montane sites, or in nutrient–rich sites such as the bases of cliffs or around large boulders. 0--3000 m; Greenland; Alta., B.C., Man., N.W.T., Ont., Que., Sask., Yukon; Alaska, Ariz., Colo., Idaho, Mont., Nev.,N.Mex., Utah, Wyo.; Mexico (alt. 3500 m); Eurasia (Iceland, n and c Europe, Greece, Caucasus, China, India, Japan); n Africa (Algeria); Pacific Islands (Hawaii).