褐色双盖蕨 he se shuang gai jue

Allantodia himalayensis Ching; Asplenium polypodioides Blume var. vestitum C. B. Clarke; Diplazium himalayense (Ching) Panigrahi; D. polypodioides Blume var. vestitum (C. B. Clarke) C. Christensen.

Plants evergreen, large. Rhizome erect, robust, up to 70 cm tall, up to 20 cm in diam., apex densely scaly; scales brown, linear or linear-lanceolate, 1.5-2 cm, membranous, margin with black narrow band, toothed, apex filiform, curly; fronds caespitose. Fertile frond more than 2.5 m; stipe dark brown, 60-120 cm, 8-15 mm in diam., base with dense scales similar to those on rhizome; lamina 2-pinnate with pinnules pinnatilobate, deltoid or ovate-deltoid, 1-1.5 m × 80-120 cm, apex acuminate; pinnae 15-20 pairs, up to 60 × 25 cm, alternate, ascending, symmetrical or nearly symmetrical; upper pinnae 7 or 8 pairs, lanceolate, 1-pinnate, sessile or subsessile; lower pinnae mostly broadly lanceolate, with stalk up to 6 cm, apex acuminate; basal pinnules broadly oblong-lanceolate, shorter; pinnules ca. 20 pairs, alternate, spreading, lanceolate, up to 14 × 4 cm, pinnatipartite to near costule, base asymmetrical, shallowly cordate at basiscopic side, subtruncate at acroscopic side, margin subentire to pinnatifid, apex shortly caudate; veins not prominent on adaxial surface, visible abaxially, pinnate, veinlets 7-10 pairs per pinnule lobe, mostly forked or pinnate, sometimes simple, ascending. Lamina herbaceous, lower parts of costules and midrib of lower pinnule lobes abaxially often with linear or linear-lanceolate brown scales, glabrous adaxially; rachis and costae dark brown, with dense dirty glandular hairs and few small scales. Sori shortly linear, 7 or 8 pairs per pinnule lobe, costular from midrib to ca. 1/2 of veinlet length, single or double on basal acroscopic veinlets; indusia brown, membranous, margin irregularly incised, opening acroscopically, gradually ruptured and part remaining. Spores reniform, perispore slightly hyaline and narrow, not rugate, prominent and average granular ornamentation.

Evergreen broad-leaved forests; 800-2400 m. N Guangxi, S Guizhou, SW Sichuan, SE Xizang, SE and W Yunnan [India, Myanmar].