1. Stegonia latifolia (Schwägrichen) Venturi ex Brotherus, Laubm. Fennosk. 145. 1923.
Weissia latifolia Schwägrichen in J. A. Schultes, Reise Glockner 2: 362. 1804; Pottia latifolia (Schwägrichen) Müller Hal.
Seta (2-)4-12 mm. Capsule stegocarpous, exerted, ovate-cylindric, to 1-2 mm, operculum short-rostrate, peristome teeth rudimentary or 16, cleft to near base. Also keying to this species is a distinctive new species described but not formally named by B. M. Murray (1992) for Alaska; a formal description will be provided in another publication. The new species shares with Stegonia the characteristic rudimentary peristome, ovate leaf with a triangle of clear cells apically and abaxial cell walls more thickened than the adaxial, and bulliform cells on the adaxial surface of the costa, but possesses three kinds of adaxial costal lamellae: (1) rounded lamellae typical of Pterygoneurum, (2) additional, serrate, papillose lamellae near the leaf apex just distal to the rounded lamellae, and (3) on small leaves only lamellae consisting entirely of bulliform, nonpapillose cells.
Varieties 2 (2 in the flora): widespread in Northern Hemisphere, Antarctic.
Stegonia latifolia is uncommon but distinctive. In section, the leaves show a characteristic thickening of the abaxial superficial cell walls, similar to that of some species of Acaulon, a genus which differs in the red laminal color reaction to KOH and spheric capsules.
