Plants: in soft, loose tufts, light to dark green or yellow-green. Stems: 0.2–3.5 cm; radiculose. Stem: leaves obovate to long-lanceolate; margins entire or serrate distally; apex obtuse, acute, or acuminate; costa ending in or before apex; proximal laminal cells rectangular; distal cells oblong-hexagonal. Sexual: condition dioicous (autoicous in S. pensylvanicum). Seta: 0.2–15.5 cm, flexuose or twisted. Capsule: not cleistocarpous, red-, orange-, or yellow-brown, or orange-red, cylindric; hypophysis with color greatly differentiated from urn, globose to turbinate, sometimes umbrelliform, elongate, usually much larger, wider than urn; annulus absent; operculum conic to hemispheric, blunt to apiculate; peristome double; exostome teeth 16, sometimes connate, reflexed when dry, inflexed when moist, of 3 layers of cells. Calyptra: conic-mitrate, small, reaching hypophysis, not constricted beyond base. Spores: 7–13 µm, smooth. Nearly worldwide, except Antarctica, tropical to subarctic regions.
Species 11 (6 in the flora). Plants of Splachnum are often shiny, entomophilous and coprophilous, and all circumboreal species appear to be restricted to growing on herbivore dung. The genus is characterized by its chambered exostome teeth as well as several species having greatly enlarged, colorful, differentiated hypophyses. The spores of this genus are sticky; the smooth setae usually continue growing after the spores mature. The stems are loosely foliate and simple or 2-fid. The stem leaves are erect or erect-spreading, usually more crowded toward stem apices, more or less contorted when dry, and usually spreading when moist. The perigonia are cupulate and large; the perichaetia are terminal on the stems or branches with leaves fewer and smaller. The exothecial cells are quadrate-hexagonal and rectangular at the capsule base, and transversely elongate in distal rows. The columella is short-exserted.