裸囊蹄盖蕨 luo nang ti gai jue

Athyrium xiangxiense S. F. Wu.

Rhizomes short, erect or ascending, apex densely scaly; scales red-brown, linear-lanceolate, apex fibriform. Fronds caespitose; fertile fronds (20-)35-78 cm; stipe brown at base, upward stramineous, shiny, (8-)15-30 cm, (1-)2-2.5 mm in diam., base similarly densely scaly, upward glabrate; lamina pinnate, oblong-lanceolate, (12-)20-35 × (3.5-)7-9 cm, base slightly narrowed, apex acuminate; pinnae (7 or)8-12 pairs, alternate, ascending, subsessile, basal 1 or 2 pairs of pinnae slightly shortened, base slightly narrowed; middle pinnae oblong-lanceolate, (1.8-)5.5-6 × 1.5-2 cm, base subequilateral, rounded-truncate, broadened, pinnatipartite to 1/2-2/3, apex shortly acuminate; pinna segments 10-12 pairs, basal segments subopposite, upper segments alternate, approximate, slightly ascending, oblong, 3-4 × 2.5-3 mm, minutely toothed, apex obtuse-rounded; veins inconspicuous adaxially, visible abaxially, pinnate in segments, lateral veins 3 or 4 pairs, oblique, simple. Lamina papery when dried, brown, glabrate, rachis stramineous, rachis and costae with sparse brownish short glandular hairs abaxially. Sori shortly linear or oblong, occasionally J-shaped or elliptic, 2 or 3 pairs per segment; indusia degenerate. Perispore surface without folds, with granular ornamentation.

● Evergreen broad-leaved forests; 400-1500 m. N Guangxi, S Guizhou, Hunan, SE Yunnan.

Athyrium pachyphyllum is very similar to A. wangii in frond morphology. However, A. pachyphyllum is different from A. wangii by the nearly exindusiate mature sori (it was incorrectly described as "exindusiate" by the original author).