Rhizome long-scandent, 1.5-2.5 mm ø; scales deciduous, fawn-coloured, triangular-acuminate, to 4 by 2 mm, the base broadened, over 20-seriate, with often laterally projecting cell-walls, the apex shortly uniseriate. Leaves c. 2-10 cm apart; petioles medium brown, often scaly at the base, terete, or adaxially in the upper part flattened or subsulcate, 10-25 cm long, about as long as the lamina. Lamina oblong, bipinnate (occasionally sterile simply pinnate ones also present), c. 15-30 cm long, with 3-9 pinnae to a side and a conform terminal one; primary rachis terete, adaxially with a distinct but shallow and very narrow groove that is usually not clearly continuous with the grooves of the lower pinnae and occasionally extends to the petiole. Pinnae ascending or upcurved, sessile, the lower ones several times their width apart, the upper ones closer, linear, c. 10-20 cm long, 11-16 mm wide, often widest near the middle, gradually and strongly narrowed in the upper 1/2 or 1/3; secondary rachises abaxially terete at the base, upward gradually bi-angular, then sulcate, or occasionally bi-angular to base, sometimes pale-angled. Pinnules c. 20-50 to a side, herbaceous, mostly dark olivaceous when dry, regularly spaced, mostly not contiguous, asymmetrically ovate to shortly ligulate, 6-10 by 3-4 mm, 2-2.5 times as long as wide, slightly ascending, the lower margin almost straight, the upper margin distally convex, a distinct outer margin not developed, the pinnule-apex rounded or narrowed-rounded. Upper pinnules gradually and strongly reduced, several denticuliform ones connected with the narrow, caudiform pinna-apex. Margins scarcely sclerotic; upper margin shallowly incised, with 3-5 incisions 1/4-1/2 mm or even less deep, the lobes slightly convex to flat; sterile pinnules crenate to subentire. Veins immersed, evident, simple or once, less often twice forked, free. Sori interrupted, mostly 1 per lobe, even though most incisions do not reach to the receptacle, shorter than the lobes, often 3-5 per pinnule, uni-to quadrinerval; indusium pale, stiff, entire or nearly so, with straight base and narrowed adnate sides, 0.5 mm wide, almost or quite reaching the margin, little reflexed at maturity. Spores hyaline, trilete, smooth, c. 22-25 μ.
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