Pylaisiella steerei Ando & Higuchi, Mem. New York Bot. Gard. 45: 211, figs. 1-34. 1987

Plants yellowish or whitish. Stems terete-foliate, regularly pinnate, branches 5 mm, creeping or rarely ascending and curved, ± complanate-foliate, partly subjulaceous; pseudoparaphyllia triangular, long-acuminate. Stem and branch leaves well differentiated. Stem leaves substraight to falcate, broadly ovate-lanceolate, gradually narrowed to apex, concave, not plicate, 1.4-1.6 × 0.4-0.7 mm; margins plane, sometimes slightly involute distally; acumen long; costa double, short; alar cells 10-15 along margins, in 5-10 rows; medial laminal cells 40-60 × 4-5 µm. Branch leaves narrowly ovate- to oblong-lanceolate, smaller, 1.2-1.4 × 0.3-0.5 mm. Seta 0.7-1.1 cm. Capsule erect, oblong-cylindric, 1.1-1.9 × 0.4-0.6 mm; exothecial cells rounded-rectangular; operculum conic, obliquely short-pointed; peristome perfect, long; exostome teeth lance-subulate, 0.3 mm, base 80 µm wide, roughly papillose distally; endostome free, basal membrane well developed, segments linear-subulate, , papillose distally, not perforate, never split, cilia simple. Spores 15-18 µm.

Capsule maturity unknown. Rotten logs and base of tree trunks, forests; moderate to high elevations; Alaska; Asia (nw China, Russian Far East).

Pylaisia steerei is the closest relative of P. polyantha. Ando and Higuchi provided full illustration, SEM micrographs of the peristome, and a detailed discussion of this species. In the flora area it is known from only three localities in Alaska. The capsules are somewhat widened at the base.