Stems 2-10 mm, central strand present, weakly differentiated, cells small. Leaves oblong to lingulate or narrowly spathulate, 1.5-2.5 mm, apices obtuse, apiculate, margins plane; costa excurrent, smooth, narrow, shorter than lamina; laminal cells 12-20 µm; basal cells rectangular, 20-60 µm, smooth; basal marginal cells weakly differentiated, longer than laminal cells, in 3-5 rows. Specialized asexual reproduction absent. Seta 4-7 mm, smooth, reddish. Capsule emergent, inclined, cylindric, 1.5-2.5 mm, strongly ribbed, brownish yellow to red, exothecial cells linear, walls thickened; peristome double, rudiments of exostome present as short nubs, teeth dark red, lanceolate, 0.25 mm, papillose, incurved when wet, erect when dry; operculum 1 mm. Calyptra 2.5-5 mm, fringed at base, smooth. Spores 35-37 µm, warty, brown.

Protected sites on calcareous soils or rock in mesic tundra; N.W.T., Yukon; Alaska.

Encalypta vittiana is similar to E. rhaptocarpa but is distinct in having dark red furrows on the capsule and a fringed calyptra. Encalypta rhaptocarpa has brown to brown-red capsules and erose calyptra bases. The two species overlap in their ranges.