6. Athyrium biserrulatum Christ, Bull. Acad. Int. Géogr. Bot. 17: 135-136. 1907.
苍山蹄盖蕨 cang shan ti gai jue
Asplenium filix-femina (Linnaeus) Bernhardi var. polyspora C. B. Clarke; Athyrium filix-femina (Linnaeus) Roth var. polysporum (C. B. Clarke) Beddome; A. polysporum (C. B. Clarke) Ching ex Mehra & Bir.
Rhizomes slender, long creeping, densely clothed with brownish, lanceolate scales. Fronds distant; fertile fronds 50-65 cm; stipe brown at base, upward stramineous, 15-20 cm, 1.5-2 mm in diam., base with sparse dark brown lanceolate scales, upward glabrate; lamina 2-pinnate, oblong, 30-45 × 14-18 cm; pinnae 15-20 pairs, basal 2 or 3(or 4) pairs of pinnae gradually shortened, opposite or subopposite, subspreading or slightly drooping, basal pinnae triangular, ca. 2.5 cm; middle pinnae lanceolate, 8-10 × ca. 3 cm, base ± rounded, shortly stalked, pinnate, apex acuminate, pinnae alternate, ascending; pinnules 10-12 pairs, deltoid-oblong, 1-1.5 cm × 5-7 mm, base somewhat inequilateral, acroscopic side often auriculate and parallel to costa, basiscopic side broadly cuneate, slightly decurrent, apex rounded and toothed; basal pinnules separated widely from each other; upper pinnules approximate, adnate to wing of costa, shallowly lobed; pinnule segments with spinelike teeth at apex. Veins visible adaxially, inconspicuous abaxially, pinnate in pinnules, lateral veins ca. 6 pairs, simple or forked. Lamina thinly herbaceous when dried, pale green or dark green, glabrate; abaxial surface of rachis and costae stramineous, with pallid short hairs. Sori oblong, J-shaped, or horseshoe-shaped, on basal acroscopic veins, biseriate along both sides of costule (often 2-4 in basal acroscopic segment); indusia pallid, large, oblong, J-shaped, or horseshoe-shaped, membranous, margin ciliate, persistent. Perispore with folds connected into large areoles. 2n = 80.
Forests, forest margins; 2000-3000 m. W Guizhou, Sichuan, SE Xizang, C and NW Yunnan [Bhutan, N India, Myanmar, Nepal, Pakistan].
Athyrium biserrulatum is very similar to African (Ethiopian) A. schimperi Mougeot ex Fee; whether they are species or subspecies requires further analysis.