无盖蹄盖蕨 wu gai ti gai jue

Fertile fronds up to 1 m; stipe upward stramineous, ca. 50 cm, 3-4 mm in diam., base clothed with brownish, lanceolate large scales, upward glabrate; lamina 2-pinnate, oblong, ca. 65 × 20-30 cm, base as wide as above, apex long acuminate; pinnae 20-22 pairs, alternate, ascending, shortly stalked (stalk ca. 1.4 mm); basal pinnae not shortened and not narrowed toward base, lanceolate, (15-)25-28 × 5-8 cm, base rounded-cuneate, pinnate-pinnatifid, apex long acuminate; pinnules ca. 25 pairs, alternate, ascending, subfalcate-lanceolate, 3.5-4 cm × 8-10 mm at base, base inequilateral, acroscopic side truncate, somewhat auriculate, parallel to costae, basiscopic side cuneate, adnate to costa, pinnatilobate to pinnatipartite (to 2/3 to costule), apex acuminate; pinnule segments 8 or 9 pairs, oblong, basiscopic basal segments smaller, long toothed, apex often deltoid; upper pinnae lanceolate, acroscopic base truncate, parallel to rachis, basiscopic base broadly cuneate, sessile, slightly curved upward, margin biserrate, apex long acuminate. Veins inconspicuous adaxially, visible abaxially, pinnate in segments, 3 or 4 pairs, oblique, simple. Lamina papery when dried, glabrate, dark green adaxially, pale green abaxially. Rachis and costae stramineous, glabrate abaxially, with very short spines on adaxial surface. Sori orbicular, abaxial on veins, 1-3 pairs per segment, exindusiate. Perispore surface with prominent folds.

Grassy areas in forests; 1000-2300 m. Xizang, Yunnan [India, Myanmar, Nepal].