Rhizome short-creeping, 2/3-2 mm ø; scales light brown, lanceolate to elongate-triangular, to 1.5 mm long, to c. 6-seriate at base, the uniseriate apex comparatively short. Leaves close; petioles slender, stramineous with darker base or brown throughout, abaxially bi-angular, 2-10 cm long. Lamina narrowly lanceolate to triangular, about as long as to 5 times as long as wide, 2.5-12 cm long, with c. 6-20 pinnae to a side; rachis abaxially bi-angular at the base, the angles fusing, mostly between the two basal pairs of pinnae, to form one keel. Pinnae slightly ascending or the basal ones spreading, ovate and crenate to linear and then usually pinnatilobate to pinnatifid, or the basal ones fully pinnate, with crenate pinnules; size and shape of pinnules strongly dependent on the degree of dissection of and the place in the lamina; larger pinnules often c. 2 mm wide, mostly obtuse. Upper pinnae and pinnules gradually reduced, confluent. Texture herbaceous to subcoriaceous, colour usually brownish or olivaceous when dry. Secondary rachises (costae) abaxially carinate, costae of smaller divisions usually rounded and obsolescent above the base. Veins immersed, abaxially ± evident. Sori uninerval, single or a few together on the lateral lobes of the larger segments, in larger lobes sometimes overtopped by a sterile part of the lobe, otherwise subterminal; indusium ¼ mm broad, ¼-½ mm long, brownish, subentire, pouch-shaped, not reaching the margin by its width or more, sometimes ruptured at maturity. Spores brownish, ellipsoidal, smooth, c. 35 by 25 μ.
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