Plants 30-80 cm tall. Rhizome ascending, 7-10 mm in diam., apex of rhizome and base of stipe with brownish black scales, scale apices ciliate and slightly curly. Fronds clustered (10-15), subdimorphic; stipe chestnut-colored, shiny, 15-40 cm × ca. 2 mm, rachis similar; lamina 2-pinnatipartite or at one side deeply bipinnate-lobed, ovate-oblong in outline, 25-40 × 15-20 cm; lateral pinnae 5-8 pairs, similar to terminal pinna in shape, opposite or subopposite, decumbent, basal pair 6-12 × 2.5-4 cm, shortly stalked, base oblique, divided nearly to costae on both or basiscopic side, apex caudate-acuminate; segments as in terminal pinna but basiscopic lobes slightly longer than acroscopic lobes, and lobe nearest base on basiscopic side longest, inclined, sometimes basal 1 or 2 segments developing into pinnule pectinately lobed on basiscopic side; terminal pinna pectinately partite nearly to costa, lanceolate in outline, 12-18 × 2-3 cm, base rounded, apex acuminate; segments 12-15 pairs, opposite, spreading, contiguous, broadly lanceolate or linear-lanceolate, somewhat falcate, 10-20 × 3-5 mm, base basiscopically not decurrent or slightly decurrent, margins of sterile fronds with long acute spinelike teeth, apex obtuse or sometimes acute; costae abaxially convex, chestnut at base, distally straw-colored, grooved adaxially, grooves with thin raised edges (minutely and irregularly toothed); veins conspicuous, decumbent, 2-forked, veinlets reaching cartilaginous point of teeth; lamina green or pale green, herbaceous when dried, glabrous. 2n = 58, 116.
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