Stereodon pratensis (Spruce) Warnstorf
Plants pale green to golden green, strongly glossy, soft, usually strongly complanate, with leaves sometimes falcate, medium-sized 0.5--1.5(--3) cm; leafy shoots 0.15--0.3 cm wide; erect to creeping, usually irregularly branched to unbranched, branches usually short, 0.02--0.1 cm; rhizoids rare to absent. Stems green to yellowish, epidermal cells hyalodermous, central strand present; pseudoparaphyllia foliose. Leaves ovate, usually tapering to a broadly acute apex, 0.5--1.8 mm, curving to insertion, margins plane and entire; alar cells not conspicuously differentiated, costa short and double or absent, median cells 80--100 × 4--5 µm, at base shorter and wider, yellowish and porose, toward apex also considerably shorter. Sexual condition dioicous; inner perichaetial leaves erect, oblong-lanceolate, plicate, margins slightly toothed or entire at tip, costa obscure. Seta reddish brown, 2--4 cm. Capsule pale brown, curved, inclined, 1--2 mm excluding conic operculum, furrowed when mature and dry, annulus 2--3 seriate; cilia of endostome 2--4.
Sporophytes produced infrequently, spring--summer, capsules mature July--Aug. Mainly terrestrial on moist soil in fens and calcareous sites; 0--3000 m; Greenland; Alta., B.C., Man., N.B., Nfld., N.W.T., N.S., Nunavut, Ont., Que., Sask., Yukon; Alaska, Colo., Ill., Ky., Maine., Md., Mass., Mich., Minn., Mont., N.H., N.Y., N.C., Ohio, Oreg., Pa., S.Dak., Vt., Wis.; Europe; Asia.
Hypnum pratense is a temperate to boreal circumpolar species, scattered largely north of the 35° parallel of latitude, but not frequent in the Arctic. For additional comments, see discussion under Hypnum lindbergii.