1. Plagiopus oederianus (Swartz) H. A. Crum & L. E. Anderson, Mosses E. N. Amer. 1: 636. 1981. (as oederiana).
Bartramia oederiana Swartz, J. Bot. (Schrader) 1800(2): 180. 1801
Stems with cortical cells lax, hyaline, walls thin, central strand present. Leaves keeled distally, 2-3.5 mm; basal laminal cell walls thinner, especially toward costa; distal cells 9-22 × 7-8 µm, striate in longitudinal rows. Seta 0.7-1.8 cm. Capsule with operculum small; exostome teeth with intermediate thickenings on internal dorsal plates not paired with cross walls on external dorsal plates; endostome basal membrane well developed. Spores 20-26 µm.
Capsules mature Jun-Sep. Soil humus, seeps, basic and acidic rock, crevices of cliffs; moderate to high elevations (200-3900 m); Greenland; Alta., B.C., N.B., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., P.E.I., Que.; Alaska, Colo., Conn., Idaho, Iowa, Maine, Mich., Minn., Mont., N.H., N.J., N.Y., Oreg., Pa., Vt., Va., Wash., Wis.; n, c Europe; Asia (China, Indonesia, Japan); Pacific Islands (Hawaii).