Distribution: Occurring on both sides of the Cascades crest in Washington; British Columbia to California, east to Alberta, Idaho, and Montana.

Habitat: Open rocky habitats from the lowlands to the midmontane.

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Mat-forming perennials, lithophytes or terrestrial; stems radially symmetric, creeping or decumbent, not easily fragmenting, forked irregularly, tips straight; main stem long and indeterminate with determinate lateral branches, ascending, 1-2-forked; rhizophores emerging from underside of stems, throughout the length of the stem, 0.2-0.4 mm in diameter.

Leaves monomorphic, arranged in somewhat alternating pseudowhorls of 4, appressed tightly or loosely, ascending, green, linear-lanceolate, generally 1.8-3.5 mm long and 0.4-0.7 mm broad, ridges on underside of leaves well defined, base rounded and adnate or cuneate and somewhat decurrent on loosely appressed stem leaves, pubescent or rarely glabrous; margins short-ciliate to finely toothed, cilia transparent, ascending toward apex; apex keeled and obtuse, occasionally attenuate or plane and attenuate, abruptly ending with short or long bristle; bristle transparent to slightly white, puberulent, sometimes breaking off, usually 0.2-0.5 mm; sporophylls usually deltate-ovate on exposed, compact mats, lanceolate-ovate on loose mats in wet habitats, ridges beneath well defined, base glabrous, margins short-ciliate to finely toothed, apex keeled, abruptly ending with short bristle, rarely tapering to bristle.

Strobili commonly paired, typically 1-4.5 cm, quadrangular; sporangia on short stalks, solitary in axil of sporophylls, opening by distal slits; spores of 2 kinds, megaspores to 4, microspores numerous.