Rhizome dorsiventrally flattened, 1.5-2.2 mm wide, short-creeping, the internodes 3-10 mm long, not white waxy, roots densely set; vascular strands 4-10, with or without sclerified sheaths; sclerenchyma strands 0-50. Rhizome scales pseudopeltate, sparsely set, slightly spreading, narrowly ovate or triangular, 1.2-3 by 0.2-0.75 mm, clathrate or subclathrate, margin denticulate, apex acute, cells longitudinally rectangular towards the apex, central region glabrous or bearing multiseptate hairs. Fronds strongly dimorphic, sessile or stipitate, herbaceous. Fertile fronds: stipe 1-32 cm, 0.5-1 mm thick; lamina simple, narrowly ovate to linear, 0.1-0.4 cm wide. Sterile fronds: stipe absent or to 3 cm long; lamina narrowly elliptic to obovate, 1.7-42 by 0.6-2.3(-2.5) cm, index 4-20, base cuneate-angustate, decurrent, forming two ridges at base of stipe, margin entire, apex rounded, rarely acute, lower surface without acicular hairs. Venation: veins more or less immersed and indistinct, 2-10 mm apart, zigzag, dichotomously branched below or at the middle, or each costal areole giving rise to two lateral veins, thus the lateral veins seemingly branching at or near the costa, connecting veins 1-2(-3), anadromous, forming more or less equally sized areoles or one row of large areoles bordered by several smaller areoles; included venation variously anastomosing, smaller veins more or less immersed and indistinct, free veinlets simple or once forked. Sori acrostichoid.
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