Description from Flora of China
Cystopteris mairei Brause; C. sphaerocarpa Hayata; C. sudetica A. Braun & Milde var. moupinensis (Franchet) C. Christensen; C. tangutica Grubov.
Rhizomes long creeping, 1-2 mm in diam., rhizomes and stipe bases clothed with brown hairs and few pale brown, broadly ovate, membranous scales. Fronds distant; fertile fronds (20-)30-40(-50) cm; stipe stramineous or chestnut-brown, shiny, 10-22(-25) cm, 1-2 mm in diam.; lamina pinnate-pinnatifid to 3-pinnate, ovate or deltoid-ovate, 9-17(-25) × 5-8(-15) cm, thinly herbaceous when dried, apex acuminate; pinnae 8-12(-15) pairs, ascending, basal pinnae oblong or ovate-lanceolate, 5-10 × 2-3.5 cm, as long as and wider than second basal pinnae, toothed, base slightly narrowed and inequilateral, with stalk 3-4 mm (2-3 mm in second basal pinnae), apex acuminate, subopposite, 3-3.5(-5) cm apart from second basal pinnae; pinnules 8-12 pairs, anadromous, alternate, usually acroscopic pinnule slightly shorter than basiscopic one, second basal basiscopic pinnule largest, deltoid-ovate or narrowly triangular, 1-2.2(-3) cm × 8-13 mm, toothed, inequilateral, acroscopic base parallel to costae, basiscopic base broadly cuneate, with stalk 1-2 mm, apex obtuse; secondary pinnules or pinnule segments 3 or 4 pairs; basal acroscopic one largest, broadly ovate, 4-9 × 3-5 mm, base cuneate and adnate to costular wing, cut or toothed at margin, apex rounded-obtuse and toothed; upper secondary pinnules rhomboid or shortly linear, apex and acroscopic side toothed. Veins visible on surfaces, 1 to several times forked, terminating in emarginations. Sori small, orbicular, abaxial on suprabasal veins, 1 or 2 sori per ultimate segment; indusia pale green or yellow-brown, orbicular or shallowly cupular, membranous, without tiny glandular hairs, covering sporangia when young, hidden at maturity. Perispore echinate.
Cystopteris moupinensis is very similar to C. sudetica but differs in the indusia without tiny glandular hairs and the plants moderately stout. The two are segregated phytogeographically: C. sudetica occurs in N and NE China, and occasionally in high mountains of Yunnan and Xizang, while C. moupinensis occurs in mountains of W China, north to Qin Ling and west to E Xizang.
Damp areas and on wet rocks in mixed forests; 1000-4100 m. Gansu, NW Guizhou, Hebei, Henan, Qinghai, Shaanxi, Sichuan, Taiwan, SE Xizang, Yunnan [N India].