22. Athyrium foliolosum T. Moore ex R. Sim, Priced Cat. Ferns. 6: 22. 1859.
大盖蹄盖蕨 da gai ti gai jue
Asplenium fimbriatum Kunze var. foliosum C. B. Clarke; A. foliosum (C. B. Clarke) C. Hope; Athyrium austroyunnanense Ching; A. fimbriatum Hooker ex T. Moore var. foliosum (C. B. Clarke) Beddome; A. submacrocarpum Ching & S. K. Wu.
Rhizomes short, erect, apex densely clothed with dark brown, lanceolate or narrowly lanceolate scales. Fronds caespitose; fertile fronds 50-75 cm; stipe dark brown at base, upward stramineous, 22-23 cm, 1.2-2 mm in diam., base similarly scaly, upward sparsely scaly, scales small or glabrate; lamina pinnate to 2-pinnate, oblong-lanceolate or broadly lanceolate, 30-56 × 7-26 cm, base gradually narrowed, apex long acuminate; pinnae 15-18 pairs, alternate, ascending or subspreading, slightly falcate, stalked (stalk 2.5-3 mm), 3 or 4 pairs of lower pinnae gradually shortened; basal pinnae narrowly ovate, 1.4-9 cm, pinnatifid; middle pinnae broadly lanceolate, somewhat falcate, 5-15 cm, base broadened, base inequilateral or subequilateral, subtruncate, auriculate, often overlapping rachis on acroscopic side, narrowly cuneate on basiscopic base, pinnate, apex long acuminate; pinnules 8-15 pairs, alternate, ascending or subspreading, subsessile; basal acroscopic pinnules largest, ovate-oblong, up to 1.3-2.5 × 0.6-1.2 cm, base equilateral, ± rounded, adnate to costa, or inequilateral, truncate, auriculate on acroscopic side, narrowly cuneate on basiscopic side, pinnatilobate to pinnatipartite, apex obtuse-acute or acute; pinnule segments 4-6 pairs, ascending, deltoid-oblong, subentire, apex obtuse or acute, with 3 or 4 crenations; upper pinnules reduced, 5-10 mm, usually decurrent and connate to wings of costa, sinuate or crenate at margin; veins somewhat visible adaxially, visible abaxially, pinnate in pinnules, lateral veins simple or forked. Lamina herbaceous or nearly papery when dried, glabrate, dark green adaxially, green abaxially; rachis and costae abaxially stramineous or slightly brownish, with sparse short hairs. Sori large, orbicular or rotund, 1 or 2 sori per segment, medial or inframedial; indusia large, mostly horseshoe-shaped or J-shaped, distal indusia pale brown, oblong, membranous, slightly ciliate or subentire at margin, persistent. Perispore hyaline, with few folds. 2n = 80, 160.
Evergreen broad-leaved forests, rock crevices on mountain slopes; 1700-2900 m. Taiwan, SE Xizang, Yunnan [Bhutan, N India, Myanmar, Nepal].
Liu et al. (Fern Fl. Taiwan, 50. 2009) argue that Athyrium foliolosum does not occur in Taiwan, where it is replaced by the similar A. tripinnatum.
The specific epithet was based on "Asplenium foliolosum" (Wallich, Numer. List, no. 2205. 1830), which is a nomen nudum and was not therefore validly published (Melbourne Code, Art. 38.1(a)). Wallichs no. 2205 included several specimens with different collection details. Some, with purplish rachises and small indusia, match Athyrium fimbriatum, whereas others, with stramineous rachises and large indusia, belong to A. foliolosum. "Aspidium squarrosum" (Wallich, Numer. List, no. 356. 1829), not D. Don (1825), is another nomen nudum that belongs here.