Small Limestone Moss

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.

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.