Zygodon mougeotii Bruch & Schimper, Bryol. Europ. 3: 39, plate 206. 1836

Plants 2-5 cm. Stem leaves linear-lanceolate, 1.5-3 mm; margins plane, entire; basal laminal cells yellowish, walls thick; distal cells 5-9 µm, slightly obscured by papillae, papillae elliptic, small. Sexual condition dioicous; perichaetial leaves elongate, narrow, base subsheathing, apex long-pointed. Seta 2.2-3.5 mm. Capsule barely exserted, 1-1.5 mm; operculum rostrate, greater than diam. of capsule. Spores 9-12µm.

Seasonally wet crevices of neutral to acidic cliffs; low to moderate elevations; Greenland; B.C., N.B., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., Que., Yukon; Ala., Alaska, Calif., Colo., Conn., Ga., Idaho, Ky., Maine, Minn., Mont., N.H., N.Y., N.C., Ohio, Oreg., Pa., S.Dak., Tenn., Vt., Va., Wash., W.Va.; Europe; Asia.

Amphidium mougeotii has linear, entire leaves and small laminal cells (5-9 µm). The cuticular papillae are numerous and elliptic, and only slightly obscure the distal cells, whereas in A. lapponicum they are larger, warty, and more noticeable.