Plants glaucous or dark green, in dense to lax tufts. Stems 0.5--1 cm. Leaves erect-appressed when dry, erect and slightly spreading when moist; narrowly lanceolate from an erect, sheathing base, 1.5--2.5 mm, shoulders well developed, form; margins plane to weakly revolute and entire proximally, plane and serrulate distal to shoulders; costa percurrent in moderately stout tip, not filling the acumen, rough abaxially in the distal portion; basal cells thin-walled, distal cells 12--25 × 4--6 µm. Sexual condition autoicous or synoicous. Seta 1--2 cm. Capsule globose to ovoid, erect, symmetrical, furrowed, 1-1.5 mm; operculum conic, beak low, blunt; peristome lacking. Spores reniform, 24--35 µm, coarsely papillose.

Capsules mature Aug.--Nov. Bare soil in montane tundra; 3500--4000 m; Colo; Europe; Asia (China; India; Japan).

Limited in the flora area to the high mountains of Colorado, this diminutive species with the erect, symmetrical capsules might be mistaken for Bartramia stricta. The latter species, however, has a well developed exostome, the leaf base is not sheathing and shoulders are lacking or, at best, weakly developed. Reports of Bartramia breviseta Lindb. (given as B. ithyphylla var. breviseta (Lindberg) Kindberg by some authors) from high elevations in Colorado likely represent misidentifications. In Bartramia breviseta the capsules are overtopped by the perichaetial leaves (the seta is 1--3 mm) and the costa fills the acumen. As presently understood, authentic Bartramia breviseta is an Arctic-alpine species of the Old World. Its precise relationship to Bartramia subulata requires further study.