Plants microscopic, annual or perennial from persistent protonema. Archegoniate plants composed of a perichaetium of a few, mainly non-chlorophyllose ecostate leaves that enclose very few archegonia. Antheridial plants reduced to a 1-stratose, 2-lipped structure enclosing a single spherical antheridium, arising from a short branch of the protonema. Seta elongate. Capsule usually obliquely oriented, upper face flat or bulging and often distinguished from lower face by a perimeter ridge, broadly ovate to lance-cylindric; operculum conic, nearly perpendicular to upper face of capsule; peristome with endostome 16-pleated, a hyaline cone, exostome of one or more rows of articulated teeth, irregular in number, sometimes rudimentary. Calyptra smooth, conic, barely covering operculum, early deciduous.
Widely distributed in temperate to subtropical regions of the Northern Hemisphere, scattered in the tropics, Pacific Islands (New Zealand), Australia.
Genus 1, species 12 (4 in the flora).