Rhizome short-creeping, 2.5-3 mm ø; scales fawn-coloured, narrowly triangular, to c. 3 mm long, to 18-seriate at base, with a very short apical uniseriate portion. Leaves clustered; petioles quadrangular with channelled sides, stramineous to olivaceous brown, their lateral faces with a series of median elongate pale pustu-les, 10-25 cm long, 1/3-1/2 as long as the lamina. Lamina to c. 70 cm long, with 5-11 major lateral pinnae to a side, a similar terminal one, and 1-5 strongly reduced basal ones. Primary rachis like the petiole, sometimes also with pustules, the adaxial groove with thick pale ridges. Pinnae alternate, ascending, subsessile, linear, the major ones 10-20 by 1.5-2 cm, broadest at base or in the basal third, evenly narrowed to the subacute to shortly acuminate apex. Secondary rachises abaxially brownish in the lower, pale in the upper part or throughout, abaxially bi-angular except for a short basal portion. Pinnules 25-35 to a side, alternate, subcontiguous to half their width apart, subsessile, herbaceous, medium or dark green when dry, slightly ascending, subtrapezoidal to semi-ovate, the upper edge convex and without an outer edge, or the upper edge straight and with a distinct outer edge; larger pinnules 9-10 by 4-5 mm. Upper/outer margin with about 4 incisions to 2 mm deep, with very narrow sinus; sterile pinnules with alternating deeper and shallower incisions; margin otherwise entire. Upper pinnules strongly reduced, denticuliform. Reduced basal pinnae with a few almost or quite sterile pinnules. Veins immersed, evident, once or twice forked, free. Sori interrupted by the incisions of the margin, usually binerval (uni-to quadrinerval); receptacle laterally exceeding the soral veins. Indusium pale, entire or nearly so, with straight or slightly convex base, often c. 1 mm long, 0.3 mm wide, narrowed at the ends, not reaching the edge by about its own width, little reflexed at maturity. Spores pale brown, smooth, trilete, c. 30 μ.
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