Plants: large, in dense tufts or intermixed with other bryophytes, dark green, rufous proximally. Stems: 1–3 cm, erect, simple or sparingly branched, tomentose proximally. Leaves: laxly erect-appressed when dry, somewhat incurved and erect-spreading when moist, ovate-lanceolate, 0.8–1.2 mm; margins narrowly revolute basally, plane distally, serrulate throughout, teeth single; apex sometimes acuminate; costa subpercurrent to excurrent, abaxial surface smooth; laminal cells papillae 1, centric, on both sides (more prominent on adaxial side); basal cells subquadrate to quadrate, 15–20 × 8–10 µm; distal cells rectangular, 15–26 × 6–8 µm. : Specialized asexual reproduction by slender brood branches in leaf axils. Sexual: condition dioicous; perigonia somewhat gemmate. Sporophytes: unknown.
Rocky cliffs, steep slopes, wet or dry sites. low to high elevations (0-2700 m). B.C., Nfld. and Labr. (Nfld.), Ont., Alaska, Calif., Mont., Vt., Wash., Wyo., e Asia (Japan, Korea).
Philonotis yezoana is easily recognized by its dark green color and centrally papillose laminal cells.