Rhizome terete, 1-3(-4) mm thick, long-creeping, internodes 10-70 mm long, not white waxy, roots densely set; vascular strands 11-17, with sclerified sheaths, sclerenchyma strands 50-100. Rhizome scales pseudopeltate, densely set, distinctly spreading, narrowly ovate or triangular, 2.5-6.5 by 1-2 mm, margin denticulate to dentate, apex acute, clathrate or subclathrate, cells longitudinally rectangular in apical part, central region glabrous. Fronds not or slightly dimorphic, stipitate, herbaceous to firm-herbaceous. Stipe 0.8-8 cm long, 0.8-3.2 mm thick; lamina simple, narrowly elliptic to obovate, 6.5-65 by 1-8 cm, index 5.5-14, base narrowly angustate, decurrent to a long wing, margin entire, occasionally sinuate, apex acuminate, lower surface without acicular hairs. Venation: veins prominent and distinct, 4-13 mm apart, more or less straight or zigzag, dichotomously branched near the margin; connecting veins 3-7, cata-or anadromous, forming equally sized areoles, included veins more or less immersed and indistinct or prominent and distinct, variously anastomosing, sometimes forming a distinct vein parallel to each vein, free veinlets simple to twice forked. Sori separate, round or elongated, 1.5-2 by 2-4 mm, superficial or slightly immersed, on the connecting veins, 1 (or 2) per vein, in two irregular rows between each pair of veins, 2-10 per sq.cm, on the whole surface of the lamina, absent in marginal areoles, generally present in costal areoles; paraphyses simple uniseriate hairs with glandular topcells, 3-or 4-celled.
Home