Bryologist 90: 15–17. 1987.
Plants in dense tufts, to 5 mm high, irregularly branched, red-brown in younger portions but black in older portions. Stems dark brown to red brown, usually somewhat hamate distally. Leaves, when dry, loosely appressed when dry, erect spreading when moist. Leaves to 2 mm long, about 5: 1, lanceolate, acuminate to the blunt or acute apex, slightly concave below. Median cells smooth throughout, arranged in regular rows, to 10 µm wide, isodiametric to transversely elongate with rounded lumens but not trigonous thickenings, incrassate with lumen/wall ratio about 1: 1. Marginal cells of leaf similar to the interior ones. Cells of median leaf base to 8 µm wide, with thick (lumen: wall ratio 1: 1) and pitted walls, 3–5: 1. Costa percurrent to shortly excurrent in the acuminate to acute apex. Costa round in cross-section with a rather well differentiated adaxial and abaxial epidermis but without guide cells. Cells of adaxial surface of costa smooth, narrowly linear with lumens often almost obscured by wall-thickening; cells of abaxial surface of costa similar to those of the lamina. Margins plane to ascending, entire throughout, not at all decurrent. Stem nearly homogeneous, of thick-walled cells without a central strand. Axillary hairs to 60 µm long, 2-celled, not offset, with one isodiametric and pale brown cell and with the other elongate and clavate, very thick-walled with lumen wall ratio about 1: 1. Rhizoids smooth and red-brown, sparingly branched, to 20 µm in basal diameter. Gemmae not seen.
Plant autoicous, perigonia on separate branches quite distant from the perichaetia. Perichaetial leaves somewhat larger than vegetative leaves, elliptic ovate with costa percurrent, to 2.5 mm long, hardly sheathing the base of the pseudopodium. Pseudopodia to 1.5 mm long, straight. Capsule dark brown except for a pale base, elliptic, 2: 1, to 1.0 mm long before dehiscence, opening by four longitudinal slits. Median exothecial cells to 25 pm wide, 3–4: 1, lateral walls thick (lumen: wall ratio 0.5–1: 1) and pitted but with thin transverse walls. Exothecial cells along lines of eventual capsule dehiscence only slightly more elongate and thinner walled than their neighbors. Exothecial cells at capsule apex not differentiated. Stomates absent. Spores to 25 µm, finely papillose, with trilete mark.