Asplenium maximum D. Don, Prodr. Fl. Nepal. 8. 1825; Allantodia maxima (D. Don) Ching; Asplenium diversifolium Wallich; Diplazium diversifolium (Wallich) J. Smith.
Plants evergreen, large. Rhizome creeping, robust, up to 3 cm in diam., with dense loose scales at apex; scales brown or chestnut, slightly shiny, lanceolate or broadly lanceolate, up to 1.5 cm, thickly membranous, margin with black band, toothed; fronds subapproximate. Stipe of fertile frond black-brown at base, upward green-stramineous, up to 1.2 m, up to 1 cm in diam., base with sparse scales similar to those on rhizome, upward glabrous, smooth or sparsely verrucose; lamina 2-pinnate with pinnules pinnatifid to pinnatipartite, deltoid, up to 1.8 × 1 m, apex acuminate; pinnae 8-13 pairs, alternate, ascending; basal pinnae largest, broadly lanceolate, up to 65 × 23 cm, with stalk up to 5 cm; pinnules up to ca. 10 pairs, alternate, subspreading, broadly lanceolate or deltoid, up to 15 × 4 cm, lower pinnules often shortly stalked, base subtruncate, slightly asymmetrical, pinnatifid to pinnatisect, apex long acuminate; pinnule lobes up to 15 pairs, slightly ascending, contiguous or approximate, oblong or subrectangular, shallowly crenate or entire, apex rounded or subtruncate, rarely acute; veins pinnate, veinlets up to 10 pairs per pinnule lobe, mostly simple, ascending, reaching pinnule margin. Lamina herbaceous when dry, pale abaxially, glabrous on both surfaces; rachis and costa green-stramineous. Sori linear, often occupying whole length of veinlet, up to 6 pairs per lobe, often single or double; indusia brown when mature, membranous, entire, opening acroscopically. Spores bean-shaped, without perispore, tuberculate ornamentation.
Valleys, evergreen broad-leaved forests, beside streamlets; 900-1800 m. Fujian, Guangxi, Guizhou, Hainan, Jiangxi, Yunnan [Bhutan, India, NE Myanmar, Nepal].
The authors have not seen material of Diplazium maximum var. brevisora Rosenstock (Repert. Spec. Nov. Regni Veg. 13: 129. 1914), described from Guizhou (Pinfa).
“Allantodia verruculosa” (Ching & W. M. Chu, Fl. Fujian. 1: 107. 1982) is a nomen nudum and was not therefore validly published (Melbourne Code, Art. 38.1(a)).