Stems creeping, not cordlike, internodes usually long, with scattered persistent petiole bases, hairs absent; scales tan to brown, ovate to lanceolate, radial walls thin, luminae tan. Leaves monomorphic, clustered at stem apex, to 45 cm, bearing sori throughout year. Petiole highly variable in color, from uniformly dark purple to uniformly straw-colored, but mostly dark purple at base, grading to straw-colored at junction with blade, shorter than blade, base sparsely scaly. Blade ovate to elliptic, 2--3-pinnate, widest at or just below middle, apex short-attenuate; rachis and costae lacking gland-tipped hairs or bulblets; axils of pinnae with occasional multicellular, gland-tipped hairs. Pinnae usually perpendicular to rachis, not curving toward blade apex, margins dentate to crenate; proximal pinnae pinnate-pinnatifid to 2-pinnate, ± equilateral, basiscopic pinnules not enlarged; basal basiscopic pinnules mostly short-stalked, base truncate to obtuse, distal pinnae deltate to ovate. Veins directed into teeth and notches. Indusia cup-shaped to lanceolate, gland-tipped hairs absent. Spores spiny, usually averaging 33--41 µm. 2 n = 84.
|Southwestern brittle fern|