Aspidium flexile Christ, Bull. Acad. Int. Géogr. Bot. 11: 252. 1902; A. melanorhizum Christ (1901), not Desvaux (1827); Dryopteris flexilis (Christ) C. Christensen; D. omeiensis (Baker) C. Christensen var. flexilis (Christ) C. Christensen; D. subthelypteris Christ ex C. Christensen; Thelypteris flexilis (Christ) Ching.

Plants 30-60 cm tall. Rhizomes long creeping or ascending, black, with sparse black-brown hairy lanceolate scales. Fronds approximate; stipes 10-30 cm, bases black, with sparse blackish brown triangular-lanceolate scales and dense glaucous short acicular hairs, distally stramineous and subglabrous; laminae narrowly lanceolate, 20-30(-40) × 6-10(-14) cm, not tapering to bases, pinnate-pinnatifid, caudate and long acuminate and pinnatifid at apices; pinnae 12-20 pairs, alternate or proximal ones opposite, obliquely spreading, sessile; proximal ones linear-lanceolate, 3.5-8 × 0.8-2.5 cm, bases symmetrical, rounded-truncate, pinnatifid and reaching narrow wings of both sides, apices shortly caudate-acuminate; segments 7-13(-15) pairs, oblong, 4-12 × 2-4 mm, margins entire, apices rounded-obtuse. Veins evident abaxially, veinlets simple, 4-9 pairs per segment, proximal pair arising from above base of costules and all reaching margins above sinuses. Laminae papery, when dry dark green, abaxially with glaucous short hairs, hairs along costae and costules dense and mixed with few acicular long hairs, adaxially with dense short acicular hairs along costal grooves, rachises with dense short acicular hairs on both sides, abaxial sides mixed with few thick and long acicular hairs and with smaller brownish tuberculate aerophores. Sori small, orbicular, attached below middle of veinlets and slightly closer to costules, 4-6 pairs per segment; sporangia each with 1 or 2(or 3) short setae near tops.

● Forests on limestone; 300-1400 m. Guizhou, Sichuan.