Distribution: British Columbia through central Oregon to California, east to Montana
Habitat: Exposed, terrestrial, often rocky sites, such as pocket of soil in ledges and cliffs
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.