中华双盖蕨 zhong hua shuang gai jue

Asplenium chinense Baker in Hooker & Baker, Syn. Fil. 237. 1867; Allantodia chinensis (Baker) Ching; Diplazium naganumanum Makino; D. orientale Rosenstock.

Plants summer-green, medium-sized. Rhizome creeping, black-brown, 5-8 mm in diam., apex densely scaly; scales brown to black-brown, lanceolate, 5-8 mm, membranous, entire, apex long acuminate; fronds approximate. Fertile frond up to ca. 1 m; stipe black-brown at base, upward dark stramineous, 20-50 cm, 2-3 mm in diam., base sparsely scaly, upward glabrous; lamina 2-pinnate with pinnules pinnatipartite to pinnatisect, deltoid, 30-60 × 25-40 cm, apex acuminate; pinnae up to 13 pairs, ascending, mostly alternate, asymmetrical (basiscopic pinnules larger), apex acuminate; basal pinnae largest, subopposite or opposite, broadly oblong-lanceolate, 20-30 × 10-12 cm, with stalk 1-3.5 cm; upper pinnae reduced, lanceolate, pinnatipartite, slightly shortly stalked or sessile; pinnules up to ca. 13 pairs, spreading, mostly alternate, symmetrical or nearly symmetrical, shortly stalked or sessile, lanceolate to oblong, 5-8 × 1.5-2 cm, pinnatifid to costa, connate to each other, with narrow wings, base broadly cuneate to shallowly cordate, apex acuminate; pinnule lobes up to 15 pairs, ascending, lobes of lower pinnules slightly free, lobes of upper pinnules approximate or contiguous, oblong to linear-lanceolate, margin dentate, or lower lobes pinnatifid, apex rounded or acute; veins pinnate, visible abaxially, not prominent adaxially, veinlets 6-8 pairs per pinnule lobe, ascending, mostly forked or simple, rarely 3-furcate or pinnate. Lamina herbaceous, grass-green or brown-green when dry, glabrous on both surfaces; rachis and costae stramineous, glabrous, shallowly grooved adaxially. Sori 5 or 6 pairs per lobe, shortly linear, occasionally narrowly elliptic to elliptic, borne from middle of veinlet or near midrib to 1/2-2/3 of veinlet length, mostly single, partly double; indusia light brown when mature, membranous, opening acroscopically, persistent or partly remaining. Spores subreniform, perispore not prominent, with irregular aculeate ornamentation. 2n = 82, 164.

Valley forests, wet broad-leaved forests, beside streamlets, rock crevices, in shade; sea level to 800 m. Anhui, Chongqing (Youyang), Fujian, Guangxi, Guizhou, S Jiangsu, Jiangxi, Shanghai, Sichuan, Taiwan (Pingdong, ?Taidong), Zhejiang [Japan, Korea, N Vietnam].