Rhizome short-creeping, 1.5-2 mm ø; scales dark reddish brown, narrowly triangular, to 2 mm long, to c. 10-seriate at base, with a short uniseriate apex. Leaves clustered; petioles stramineous to pale brown, quadrangular, occasionally with pal er angles, abaxially flat to shallowly sulcate, at the base often dark-verruculose, 8-45 cm long, equaling to over twice as long as the lamina. Lamina bipinnate (very rarely onee pinnate and fertile), with 1-4, most often 2 or 3 pinnae to a side and a conform terminal one; primary rachis like the petiole, often more distinctly pale-margined, abaxially usually sulcate. Pinnae ascending, subsessile, linear, their width apart to contiguous, 10-20 cm long, 1.7-2.5 cm wide, widest in the lower third or the middle, gradually and strongly tapering to the often long-acuminate apex; terminal pinna often the longest and widest; secondary rachises abaxially broadly and ± shallowly sulcate, sometimes pale-margined. Pinnules c. 25-40 to a side, half their width apart to contiguous, spreading or mostly ascending, herbaceous, medium to dark or blackish green when dry, translucent, 1/4-elliptic, narrowed and obtuse to subacute, 7-15 mm long, 2.5-5 (often 4) mm wide, 2.5-3 times as long as wide, almost evenly narrowed throughout, the upper margin outward increasingly convex, with 3 or 4 major incisions, the inner ones reaching to 1/4 or 1/3, or rarely to 1/2 the outer ones to 1/2 or slightly beyond, with acute sinus; at least the broader lobes with convex outer margin, the lateral margins almost parallel, the major ones often shallowly incised again, otherwise entire, a distinct outer margin not developed. Upper pinnules strongly reduced, some denticuliform ones confluent with the narrow, ± caudiform terminal segment. Veins immersed, evident, mostly twice forked, regularly anastomosing, with one series of areoles, one under each incision, c. 3/4 mm wide, the lobes containing 2-5 vein-ends. Sori joining all vein-ends of a lobe; receptacle at least in larger lobes distinctly convex; indusium pale, entire, 0.3-0.4 mm wide, reaching the margin or very nearly so, ± reflexed at maturity; sporangia often spreading beyond the pinnule margin. Spores rather pale brown, trilete, smooth or almost so, c. 21-23 μ.
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