Rhizome dorsiventrally flattened, 2.5-8 mm wide, short-creeping, internodes up to 20 mm long, not white waxy, roots sparsely to densely set; vascular strands 6-16, with sclerified sheaths, sclerenchyma strands absent. Rhizome scales pseudopeltate, densely set, appressed to distinctly spreading, ovate, narrowly ovate or triangular, 1-4.5 by 0.5-1.2 mm, margin denticulate, apex acute, clathrate or subclathrate, central region glabrous. Fronds not or slightly dimorphic, stipitate, thin-herbaceous. Stipe up to 7.5 cm long, 2.5-5 mm thick; lamina simple, narrowly elliptic, obovate to linear, 35-95 by 1-9 cm, index 7.5-40, base narrowly angustate, decurrent to a long wing, margin entire, apex acuminate, lower surface with acicular hairs. Venation: veins prominent and distinct, 5-18 mm apart, more or less straight, dichotomously branched about the middle to near the margin, catadromous; connecting veins forming one row of large areoles parallel to the costa, bordered by several smaller areoles; costal areole, if present, formed by smaller veins; included venation prominent and distinct, variously anastomosing; free veinlets simple to twice forked. Sori separate, round or elongate along the veinlets, superficial or slightly immersed, 0.5-1.5 by 1-3 mm, irregularly scattered on the smaller anastomosing veins and free including veins, 10-65 per sq.cm, on the whole surface of the lamina, present in marginal and costal areoles; paraphyses simple uniseriate hairs with glandular topcells, 2-4-celled (occasionally with a 1-celled subapical acicular branch), sporangium annulus 18-23-celled, indurated cells 12-16.
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