17. Hypnum pratense Koch ex Spruce, London J. Bot. 4: 177. 1845.
Breidleria pratensis (Koch ex Spruce) Loeske; Hypnum pseudopratense Kindberg; Stereodon pratensis (Koch ex Spruce) Warnstorf
Plants medium-sized, pale green to golden green. Stems 0.5-1.5 (-3) cm, green to yellowish, erect to creeping, , irregularly branched to unbranched, branches 0.1-0.3 cm; hyalodermis present, central strand present; pseudoparaphyllia foliose. Leaves sometimes falcate, not strongly secund, ovate, , tapering to apex, 0.5-1.8 × 0.3-0.5 mm; base decurrent; margins plane, entire; apex broadly acute; costa double and short or ecostate; alar region not conspicuously differentiated; basal laminal cells shorter, wider than medial cells, yellowish, walls porose; medial cells 80-100 × 4-5 µm. Sexual condition dioicous; . Seta reddish, 2-4 cm. Capsule inclined to arcuate, pale brown, short-cylindric, 1-2 mm; annulus 2- or 3-seriate; operculum conic; endostome cilia 2-4.
Capsules mature Jul-Aug. Terrestrial, moist soil in fens, calcareous sites; low to high elevations (0-3000 m); Greenland; Alta., B.C., Man., N.B., Nfld. and Labr. (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; plants produce sporophytes infrequently in spring and summer. Plants of H. pratense are strongly glossy with few or no rhizoids, the apical laminal cells are considerably shorter than the medial cells, and the capsules are furrowed when mature and dry. For additional comments, see discussion under 14. H. lindbergii.