Rhizome long-scandent, wiry, 1/2-3/4 mm ø, atropurpureous to blackish, lustrous, soon devoid of scales; scales honey-coloured, narrowly triangular, to 2 mm long, to 8-seriate at base, the uniseriate apex of one cell or wanting. Leaves remote, 1.5-5 cm apart; petioles stramineous except for the dark base, quadrangular almost to base, at least adaxially sulcate, 4-15 cm long, shorter than the lamina. Lamina narrowly oblong, 8-25 cm long, 2-3.5 cm wide, with 15-30 pinnules to a side; rachis similar to the petiole, upward narrowly green-margined. Pinnules herbaceous, olivaceous when dry, spreading, their width apart to subcontiguous, mostly alternate except the basal ones; larger pinnules semi-ovate in outline, 10-18 mm long, 5-8 mm wide, 2-2.5 times as long as wide, deeply pinnatifid from the upper margin, with 3-4 primary segments, the inner one or two forked; segments 0.3-0.6(-1) mm wide at the base, 0.5-1.5(-2) mm wide at the sorus, gradually widened below, more suddenly at the sorus, connected by a wing 1/4-1/2 mm wide, rounded and erose to irregularly corniculate at apex. Sterile segments not broadened at apex, acute or subacute. Basal pinnules more remote and sometimes slightly reduced; upper pinnules (in the upper 1/3 or 1/2) reduced, the uppermost confluent into a small pinnatifid leaf-apex. Veins immersed, evident, solitary in the lobes. Sori solitary near the apices of the lobes, uninerval; indusium delicate, ovate to hippocrepiform, subentire, free at the sides, 0.3-0.5 mm wide, 0.5-1 mm long, not reaching the margin by 1-2 times its width, scarcely reflexed at maturity. Spores very pale, trilete, smooth, c. 22 μ.
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