Plants small, not polytrichoid, gregarious, often in extensive colonies on soil. Stems unbranched. Leaves only slightly sheathing at base, distinctly concave to channeled, cucullate, the apex obtuse or apiculate; lamina broad and 1-stratose, margins entire or bluntly and irregularly toothed distally by projecting ends of rhomboidal marginal cells, forming an indistinct border; costa smooth at back or roughened near apex, rarely with a few low adaxial lamellae; lamellae restricted to costa, transversely undulate, margins entire or incised and irregularly dentate, marginal cells in section undifferentiated, smooth. Sexual condition dioicous; male plants smaller, perigonia conspicuous, cupulate, bracts broadly ovate, flaring at apex; perichaetial leaves erect, lanceolate, often much longer than stem leaves. Capsule moderately to strongly curved and cylindric to gibbous and asymmetric, wrinkled when dry, not angled, tapering to base; exothecium smooth, exothecial cells short to longitudinally elongate, often with thickened radial longitudinal walls, no thin spots or pits; stomata superficial, at base of capsule; operculum rostrate; peristome deeply divided to below capsule rim, the teeth 32, linear, crowded, at times poorly formed and irregular in shape. Calyptra smooth or roughened at tip. Spores large (20-25 µm), finely papillose.
|[Greek psilos, naked, and pilon, hair, alluding to calyptra]|