Stems compact, erect to ascending, with a few persistent petiole bases of unequal lengths; scales often uniformly brown but at least some bicolored with dark central stripe and pale brown margins, narrowly lanceolate. Leaves 5--25 × 1.5--6 cm. Petiole light brown or straw-colored throughout when mature, occasionally darker at very base, not articulate above base, relatively brittle and easily shattered. Blade narrowly lanceolate to ovate, pinnate-pinnatifid to 2-pinnate proximally, sparsely to moderately glandular, never viscid; glandular hairs with thin stalks and slightly expanded tips; rachis with glandular hairs and occasional hairlike scales. Pinnae ovate-deltate to elliptic, longer than wide, abruptly tapered to a rounded or broadly acute apex, occasionally attenuate; largest pinnae with 4--9 pairs of pinnules; abaxial and adaxial surfaces glandular, lacking nonglandular hairs or scales. Pinnules dentate, often shallowly lobed; margins lustrous adaxially, usually thickened, lacking cilia but sparsely glandular, with occasional 1--2-celled translucent projections. Vein tips enlarged to form whitish hydathodes visible adaxially. Indusia of relatively broad segments; segments multiseriate most of length, usually divided and uniseriate distally, composed of ± isodiametric cells, often surpassing mature sporangia. Spores averaging 43--49 µm. 2 n = 152. Sporulating late spring--fall. Shaded ledges and alcoves near springs and seeps; usually on granitic or volcanic substrates; 1000--2200 m; Ariz., N.Mex.; n Mexico. Woodsia cochisensis traditionally has been identified as W . plummerae or (rarely) W . mexicana Fée. It is readily separated from W . plummerae by the characteristics given in the key, and from North American members of the mexicana group ( W . phillipsii and W . neomexicana ) by having indusial segments that are broad and nonfilamentous at the base. Woodsia cochisensis is less glandular than typical W . mexicana from northeastern Mexico and is further distinguished from that species by the thickened, lustrous pinnule margins and well-developed hydathodes. Isozyme and chromosome studies suggest that W . cochisensis is an allotetraploid that may have originated through hybridization between W . phillipsii and an undescribed Mexican diploid (M. D. Windham 1993). It crosses with the former species to produce sterile triploids of intermediate morphology.