Stems short, ascending, usually unbranched, densely clad with scales and persistent long leaf bases; scales with very prominent cell walls, darker central stripe absent.
Leaves often wintergreen but not fully evergreen, up to approximately 15 cm long.
Petioles short, up to 33–50% the leaf length, glossy yellowish brown at the base, green above, adaxial side often grooved, not winged; rachis green; petiole and rachis with sparse narrow lattice-like scales and glandular hairs.
Blades linear, 1-pinnate, to approximately 10 × 1.5 cm.
Pinnae ovate or deltate, to 7 × 5 mm, sparsely glandular-hairy; margins with few broad rounded or obtuse teeth; apex rounded; base unequal.
Sori linear to oblong, to 2 mm long, on lateral veins diverging from the costa at an acute angle, usually 2–6 sori per segment; indusia pale, borne on 1 side of the sorus and partially covering it.
2n=36.
Moist crevices in shaded limestone outcrops. 2000–2400 m. BW. CA, ID, NV, WA; western and northeastern North America; Eurasia. Native.