Plants to 3 cm high, in dark green to brownish green or dark brown mats or tufts with the loosely spreading stems loosely spreading and curled upwards at their ends. Leaves erect-spreading when moist but rigidly appressed when dry, narrowly ovate-lanceolate and broadest near the base, with bluntly acute to somewhat obtuse apices, to 3 mm long, about 4: 1. Median laminal cells uniformly bistratose, arranged in very well defined rows, isodiametric or somewhat elongate with rounded lumens, thick-walled and trigonous, to 12 µm wide, with 2 or sometimes 3 unbranched papillae on each surface. Basal marginal cells to 14 µm wide, quadrate and isodiametric, pellucid and smooth, with hour-glass-shaped end walls. Basal juxtacostal cells smooth, elongate, to 4: 1, with lateral walls thick and sinuose, sometimes pitted. Cells on adaxial surface of costa elongate and pitted in 1–2 rows. Margins entire and plane throughout, auriculate at base, bi- to tri-stratose. Costa percurrent or nearly so, not in a well-defined keel. Costa cross-section essentially homogeneous, about 4 cells thick, and composed of 4–6 cells adaxially and about 10–12 cells abaxially. Centrally inserted axillary hairs to 20 cells (500 um) long but the lateral ones only 3 cells (60 um) long; all with a single basal brown cell, not offset from leaf insertion. Rhizoids to 25 µm in diameter at insertion, abundant near the base of the plant, smooth, red-brown, sparingly branched. Stem rounded pentagonal in cross-section, without a central strand and with a 2–3 layered stereome of strongly pachydermous, red brown cells surrounding several layers of larger and somewhat pachydermous, hyaline inner corticals.
Autoicous with perigonia in leaf axils below the perichaetia. Perichaetia terminal with bracts little differentiated from the vegetative leaves. Capsule somewhat emergent on a yellow to yellow brown, smooth and erect seta to 1.5 mm in length. Urn, above the long and twisted neck, brown to dark brown, to 1.5 mm long, 2–3: 1, erect, somewhat strangulate and lightly sulcate with eight ribs which extend onto the long and wrinkled neck. Operculum conic-apiculate. Annulus well-defined, revoluble. Exothecial cells unistratose in cross-section with the outer walls very much thickened and bulging, but with the inner walls very thin. Exothecial cells at capsule mouth not strongly reddened, to 20 µm wide, quadrate with rounded lumens in up to 5 rows. Exothecial cells at middle of urn rather thick walled with lumen: wall ratio 2–4: 1, short rectangular, 2–4: 1, to 20 µm broad, mostly thicker-walled on the ridges and thus well differentiated from the cells in the valleys of the strongly sulcate capsule. Stomata phaneroporous, primarily located below the middle of the urn. Exostome teeth reflexed when dry, initially fused in pairs but later separating, pale brown, to 250 µm long, finely and densely papillose. Endostome segments 8, about as long as the exostome, lightly or not at all papillose, comprised of two parallel rows of cells. Calyptra campanulate, very lightly plicate with its cells not at all papillose. Hairs sparsely arranged on calyptra, arising from its low ridges, with their cells multiseriate and papillose. Spores green, to 20 µm, finely papillose.
![University of California [UC]](http://ucjeps.berkeley.edu/common/images/logo_uc_80.png){kind=logo}
