4. Pseudoleskea patens (Lindberg) Kindberg, Canad. Rec. Sci. 6: 20. 1894.
Lescuraea patens Lindberg, Meddeland. Soc. Fauna Fl. Fenn. 14: 75. 1888 (as Lesquereuxia)
Plants small to medium-sized, in thin mats, dark green, olive green, black-green, or rarely yellow-green. Stems with branches slender to robust, julaceous, apices sometimes curving up; central strand present; paraphyllia many, filamentous to foliose, not branched. Leaves appressed to julaceous when dry, erect-spreading to patent when moist, dull, ovate, asymmetric, not or rarely falcate, (0.6-)0.7-1 mm; margins recurved proximally; apex abruptly acute to rarely short-acuminate, hair-point absent; costa not reaching acumen, green to orange-green, somewhat sinuate, ; alar cells quadrate to transversely elongate, region large; medial laminal cells quadrate, to 18 µm, 1(-2):1, opaque, moderately to strongly low rounded papillose over lumen or papillae sometimes off-centered, walls incrassate, not pitted; proximal juxtacostal cells usually shorter than medial, walls pitted or not. Capsule inclined, asymmetric, 0.5-2 mm; endostome basal membrane 1/3-1/2 exostome length, segments shorter than exostome, cilia well developed. Spores 10-14 µm.
Capsules mature summer (Jul-Aug). Shaded to exposed rock and outcrops, mineral soil, near streams; moderate to high elevations (900-3500 m); Alta., B.C., Nfld. and Labr., N.W.T., N.S.; Alaska, Calif., Colo., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.; Eurasia.
Pseudoleskea patens is relatively small and usually dull, dark, or olive green, with short laminal cells with rounded centrally located papillae; it differs from P. tribulosa by the recurved margins, weaker and lower laminal cell papillae lacking projecting apical salient, larger leaves with stronger plicae, and lack of the Morningstar-shaped projections of the abaxial apex cells of the costa.