Plants tiny, olive-green to light green. Leaves lanceolate, to ovate-lanceolate, often stoutly subulate from broader base, narrowly obtuse to broadly acute; costa ending in apex or filling it; margins entire to crenulate; leaf cells (1--)2:1; perichaetial leaves larger and longer than vegetative leaves, somewhat differentiated. Seta 1--1.5 mm, slightly curved, stout. Capsule hemispheric to obovate-turbinate, flaring at mouth when old; peristome of 16, broad, well-developed teeth; columella exserted. Spores (15--)18--24 µm.

Calcareous cliffs; B.C., Nfld., N.S., N.W.T., Que., Yukon; Alaska, Colo., N.H., Vt.; Europe.

Seligeria tristichoides is relatively frequent in Alaska and western Canada, and is disjunct in Colorado and in the east ranges from Newfoundland south to Vermont. This tiny gregarious species has a persistent columella and well-developed peristome. These features, along with the turbinate capsules and subulate vegetative leaves with costa filling the apex, are diagnostic. As the epithet attests, the leaves are often somewhat three-ranked.