Bryum pallescens Schleicher ex Schwagrichen, Sp. Musc. Frond. Suppl. 1(2): 107, plate 75 [right]. 1816

Plants in dense or open turfs, green or yellow-green. Stems 1-3(-4) cm, comose, innovations comose or somewhat elongate and evenly foliate; somewhat radiculose. Leaves green, twisted to contorted when dry, ovate-lanceolate, flat to weakly concave, (1-)2-3(-3.5) mm, somewhat enlarged toward stem apex; base weakly decurrent; margins revolute to mid leaf or beyond, limbidium strong, in 2 or 3 rows; apex acuminate; costa long-excurrent, awn ± smooth; proximal laminal cells 3-4:1, same width or sometimes wider than more distal cells; medial and distal cells rhomboidal, 14-22 µm wide, 3-4:1, walls usually thin to firm. Specialized asexual reproduction absent. Sexual condition autoicous. Seta 1-2(-3) cm. Capsule brown, elongate-pyriform, symmetric, 2-4 mm, mouth yellow; operculum conic, apiculate; peristome well developed; exostome teeth yellow basally, hyaline distally, lamellae usually straight mid tooth, pores absent along mid line; endostome not adherent to exostome, basal membrane high, 1/2 exostome segments with elongate oval perforations, cilia long, appendiculate to nodose. Spores 18-22 µm, finely papillose, pale brown-yellow or green.

Capsules mature May-Aug. Damp to wet soil; low to high elevations (0-3300 m); Greenland; Alta., B.C., Man., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., P.E.I., Que., Sask., Yukon; Alaska, Ariz., Calif., Colo., Idaho, Maine, Mass., Mich., Minn., Mo., Mont., Nev., N.H., N.Dak., Ohio, Oreg., Pa., S.Dak., Utah, Vt., Va., Wash., W. Va., Wis., Wyo.; South America; Eurasia; Pacific Islands (New Zealand).

Ptychostomum pallescens is a common widespread boreal-temperate species favoring wet soil in wetlands, along streams, and in springs. The costal awns are pigmented. Ptychostomum creberrimum is similar, but has smaller spores, synoicous sexual condition, and ovate segment perforations.