Rhizome short-creeping, 2 mm ø; scales dark castaneous, to 1.25 mm long, almost acicular, up to 3-seriate at base, the apex long, uniseriate. Leaves clustered; petioles dark brown or black, lustrous, adaxially flattened and with two pale lateral ridges, abaxially usually keeled in the upper part, 6-18 cm long, 1/4 as long as to equaling the lamina. Lamina very narrowly oblong, 8-20 cm long, (1-)2.5- wide, scarcely or not narrowed at the base, very shortly narrowed at the apex, with up to c. 30 pinnules to a side; rachis abaxially keeled or rarely basally subterete, the keel at least upward pale, otherwise the rachis like the petiole. Pinnules chartaceous, mostly drying green, spreading or the basal ones deflexed, asymmetrically ovate to lanceolate, (5-)10-20 mm long, (3-)5-7 mm wide, 2-3.5 times as long as wide, broadly rounded to subacute; the base at the upper side sharply rectangular to shortly auriculate. Lower pinnules not, a few upper ones slightly, or no upper pinnules reduced, the terminal pinnule free, rhombic to asymmetrically triangular. Articulation at pinnule-bases distinct. Fertile pinnules entire, sterile ones crenate-sinuate or rarely lobed. Veins immersed but abaxially mostly evident, mostly twice forked; costa weak, diagonal, not percurrent. Sori unbroken, occupying the upper and outer or also part of the lower margin; indusium yellowish to green, entire, 0.3-0.4 mm wide, equaling the margin, ± reflexed at maturity. Spores rather pale brown, trilete, verruculose, c. 22 μ.
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