Description from Flora of China
Aspidium pellucidum Franchet, Nouv. Arch. Mus. Hist. Nat., sér. 2, 10: 119. 1887; Cystopteris alata Ching; Dryopteris pellucida (Franchet) C. Christensen; Nephrodium pellucidum (Franchet) Diels.
Rhizomes long creeping, ca. 2 mm in diam., rhizome and stipe bases densely clothed with red-brown short hairs, and few pale brown, broadly ovate, membranous scales. Fronds distant; fertile fronds (20-)50-60 cm; stipe pale stramineous or brownish red, shiny, (10-)20-32 cm, 1-2 mm in diam., with few pale brown, broadly ovate, membranous scales mixed with short hairs at base; lamina 3-pinnate, ovate to narrowly ovate-oblong, (10-)20-33 × (5-)10-15(-25) cm, thinly herbaceous or submembranous when dried, apex long acuminate; pinnae (10-)12-15(-17) pairs, ascending, subopposite, basal pinnae longest, deltoid-lanceolate, (5-)8-14 × 2.5-4.5 cm, base inequilateral, with stalk 3-5(-8) mm, apex caudate-acuminate, (3-)5(-7) cm apart from second basal pinnae; pinnules 8-12 pairs, anadromous, alternate, usually acroscopic one slightly smaller than basiscopic one, second basal basiscopic pinnules largest, narrowly ovate or narrowly triangular, 1.5-2.5(-4) × 1-1.5 cm, base very inequilateral, acroscopic base narrowly cuneate, parallel to costae, basiscopic base broadly cuneate, very shortly stalked or subsessile, apex acute or subobtuse and toothed; secondary pinnules or pinnule segments 3-5 pairs, basal acroscopic one largest, oblong or ovate, rounded-obtuse or subtruncate at apex, toothed at apex and margin; veins visible on surfaces, more obvious abaxially, simple or 1- or 2-forked, terminating in emarginations. Sori brown, orbicular, abaxial suprabasally, 1 or 2 sori per ultimate segment; indusia pale brown, orbicular or half cup-shaped, membranous, without tiny glandular hairs, covering sporangia when young, hidden at maturity. Perispore echinate. 2n = ca. 84*.
Cystopteris pellucida is very similar to and sympatric with C. moupinensis but differs in the plants slightly larger, ultimate segments wider, and lamina thinner. The indusia are larger and attached up to 2/3 of the circumference of the receptacle.
● Forests on mountain slopes, damp areas at streamsides; 1500-3700 m. S Gansu, Henan, Shaanxi, W Sichuan, Xizang, Yunnan.