Plants ephemeral, minute, light green. Stems very short from thick or somewhat thin protonematal mats, protonema persistent. Leaves few, contorted or not, linear- or ovate-lanceolate; apex acuminate to acute; margins plane, entire to serrate, often coarsely so, distally or to near base; costa none or occasionally weak; upper and median cells large, narrowly long hexagonal to rhomboidal, smooth to papillose by projecting distal cell angles; basal cells larger and broader, irregularly rectangular. Autoicous, dioicous, or polygamous. Perichaetia terminal, leaves larger. Capsules cleistocarpous, immersed, sessile or nearly so, ovoid to globose, apiculate or not, indehiscent or dehiscent near mid region, exothecial cells smooth to weakly or strongly bulging; stomata superficial, surrounded by 2 guard cells, restricted toward base or scattered throughout, occasionally absent; opercula absent. Peristome absent. Calyptrae mitrate, base weakly lobed or erose. Spores reniform, mostly large, papillose.