21. Diplazium doederleinii (Luerssen) Makino in C. Christensen, Index Filic. 231. 1906.
光脚双盖蕨 guang jiao shuang gai jue
Asplenium doederleinii Luerssen in Engler, Bot. Jahrb. Syst. 4: 358. 1883; Allantodia doederleinii (Luerssen) Ching; Asplenium nudicaule (Copeland) Dunn & Tutcher; Athyrium doederleinii (Luerssen) Ohwi; A. nudicaule Copeland; Diplazium aridum Christ; D. costalisorum Hayata; D. inflatisorum Hayata; D. morii Hayata; D. nudicaule (Copeland) C. Christensen.
Plants evergreen, medium-sized. Rhizome creeping, dark brown, 1-1.5 cm in diam., apex with sparse adpressed brown scales, elsewhere glabrous; fronds sparse or approximate. Fertile fronds up to 1.7 m; stipe black-brown at base, upward green-stramineous or light brown-stramineous, up to 80 cm, 4-5 mm in diam., base usually with few fleshy processes, upward sparsely scaly along length; scales deciduous, often adpressed, brown, ovate, broadly lanceolate, or lanceolate, membranous, margin sparsely serrate, sometimes prominently black; lamina 2-pinnate with pinnatilobate pinnules, deltoid, up to 90 × 60 cm, apex acuminate; pinnae up to ca. 10 pairs, alternate, ascending, lower pinnae broadly oblong-lanceolate, pinnate, stalked, basal 2 pairs largest, up to 40 × 20 cm, with stalk up to 5 cm; pinnules up to ca. 15 pairs, alternate, subspreading, lanceolate or broadly oblong-lanceolate, up to 11 × 3 cm, base asymmetrical, shallowly cordate or truncate on basiscopic side, broadly cuneate on acroscopic side, shortly stalked, margin pinnatilobate to pinnatipartite, apex acuminate; pinnule lobes up to ca. 10 pairs, ascending, oblong or suboblong, margin entire or sparsely shallowly crenate, apex rounded or rounded-cuneate; veins visible, pinnate, 7 pairs per pinnule lobe, ascending, forked or simple, occasionally 3- or 4-furcate. Lamina thinly papery or papery when dry, olive-green or brown-green, dark colored adaxially, both surfaces glabrous; rachis and costa green-stramineous, glabrous, grooved adaxially. Sori shortly linear or oblong, 5 pairs per lobe, mostly single, few double, costular; indusia membranous, light brown, vaulted, irregularly ruptured on back. Spores bean-shaped, perispore prominent, few rugate. 2n = 246 (apomictic).
Broad-leaved forests in wet valleys; 300-2300 m. Fujian, Guangdong, Guangxi, Guizhou, Hunan, Sichuan, Taiwan, Yunnan, Zhejiang [Japan, Vietnam].