薄叶双盖蕨 bao ye shuang gai jue

Athyrium pinfaense (Ching) Ohwi.

Rhizome oblique or erect, dark brown, with dense fleshy thick roots, apex with brown, lanceolate, entire scales; fronds caespitose. Fertile frond ca. 65 cm, stipe brown at base, upward green-stramineous, ca. 30 cm, ca. 2 mm in diam., base with dense scales similar to scales on rhizome, upward glabrous, grooved on adaxial side; rachis stramineous or green-stramineous, slightly glossy, shallowly grooved on adaxial side; lamina 1-imparipinnate, ovate, ca. 34 × 22 cm, base rounded-cuneate; lateral pinnae 2 or 3 pairs, oblique, subfalcate, lanceolate, base mostly nearly symmetrical, rounded-cuneate, whole margin serrate or biserrate, sometimes slightly pinnatilobate, apex long acuminate; basal pinnae asymmetrical, acroscopic base rounded, basiscopic base cuneate, shortly stalked, upper pinnae sessile or slightly adnate; apical pinna lanceolate, similar to lateral pinnae, base often asymmetrical, broadly cuneate; costae rounded and swollen on abaxial side, shallowly grooved on adaxial side; veinlets prominent on both surfaces, oblique, 2-4 times forked, 6 per vein group, thin, reaching teeth of lamina margin. Lamina herbaceous, grass-green when dry, glabrous. Sori and indusia long linear, slightly curved, not on all veinlets, often borne on acroscopic veinlets, mostly single, sometimes double, catadromous veinlets sometimes fertile with sori short. Spores semicircular in equatorial view, perispore hyaline, with sometimes aculeate projections.

Chongqing, Fujian, Guangxi, Guizhou, Hunan (Jishou), Jiangxi (Anyuan), Sichuan (Emei Shan), Yunnan (Maguan), Zhejiang (Longquan) [Japan].