镰羽双盖蕨 lian yu shuang gai jue

Allantodia griffithii (T. Moore) Ching; Athyrium griffithii (T. Moore) Milde.

Plants evergreen, medium-sized. Rhizome creeping, black-brown, up to ca. 1 cm in diam., apex densely scaly; scales black or black-brown, lanceolate or linear-lanceolate, thickly membranous, distal margin toothed; fronds approximate to caespitose. Fertile frond 0.5-1 m; stipe black-brown at base, upward stramineous or green-stramineous, 20-50 cm, 2-3 mm in diam., base with sparse scales similar to those on rhizome, upward glabrous, shallowly grooved adaxially; lamina 1-pinnate with pinnae pinnatifid to pinnatisect, or lower part 2-pinnate, deltoid, 20-50 × 20-30 cm at base, apex acuminate; pinnae 8-10 pairs, alternate, slightly ascending or spreading, sickle-shaped lanceolate, asymmetrical (wider on basiscopic side), up to 20 × 3-5 cm, stalked (stalk ca. 2 cm), base shallowly cordate or broadly cuneate, pinnatipartite or pinnate on basiscopic side, apex caudate or long acuminate; free pinnules of lower pinnae 1 or 2 pairs, pinna lobes up to ca. 15 pairs, subspreading, approximate or contiguous, sickle-shaped lanceolate or suboblong, margin serrate, occasionally pinnatilobate, apex shortly acuminate or rounded; veins visible abaxially, not prominent adaxially, pinnate; veinlets of lower pinnae usually 2-furcate, ascending. Lamina firmly herbaceous when dry, gray-green, glabrous on both surfaces; rachis green-stramineous, glabrous, shallowly grooved adaxially. Sori shortly linear, from costule or near costule to below lamina margin, up to 10 pairs per pinna lobe, mostly single or double on basal acroscopic veinlet, or occasionally forked; indusia brown when mature, membranous, entire, opening acroscopically, persistent. Spores bean-shaped, perispore hyaline, few rugate.

Evergreen broad-leaved forests; 1000-1900 m. W Guangxi (Baise), S Guizhou, S Hunan (Wugang), SE Yunnan (Jinping, Maguan, Yuanyang) [NE India, N Vietnam].