Plants large. Rhizome creeping, black-brown, apex sparsely scaly; scales brown, ovate, thickly membranous, entire, adpressed; fronds distant. Fertile frond up to 2 m or longer; stipe green-stramineous, up to 80 cm, densely scaly; scales similar to those on rhizome, attached by peltate base, some scales borne on stiff, conical, shortly aculeate processes, stipe prickly after scales fallen; lamina 3-pinnate with pinnatilobate secondary pinnules, deltoid, up to 1.2 × 1 m, apex acuminate; pinnae up to ca. 10 pairs, alternate or subopposite, ascending, ovate or deltoid, up to 80 × 30 cm, base truncate, with stalk ca. 6 cm, apex acuminate; primary pinnules up to 14 pairs, alternate, subspreading, with stalk up to 3 cm, oblong-lanceolate, up to 25 × 10 cm, base truncate, apex acuminate; secondary pinnules up to ca. 10 pairs, alternate, spreading, lanceolate, up to 6 × 2.5 cm, base broadly cuneate, slightly asymmetrical, shortly stalked, remainder decurrent, pinnatipartite, apex usually acute, occasionally acuminate; lobes of secondary pinnules up to ca. 8 pairs, ascending, oblong, up to 1 cm × 4 mm, margin pinnatilobate or serrate, sometimes shallowly repand, apex rounded; upper ones subentire; veins pinnate; veinlets forked or simple, rarely trifurcate. Lamina thinly herbaceous or membranous, green when dry, glabrous on both surfaces; rachis and costa stramineous, sparsely prickly abaxially, shallowly grooved adaxially. Sori ovate, 1 per ultimate lobe, usually single, few double; indusia gray, ovate, bullate, thinly membranous, irregularly ruptured on back, disappearing. Spores reniform, perispore hyaline, without rugate, granular ornamentation.
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