Description from Flora of China
Plants small, epiphytic. Rhizomes radial, with stipes in whorls; scales not clathrate, glabrous. Stipe not articulate to rhizome, phyllopodia absent. Lamina linear to linear-oblanceolate, base long attenuate, margin entire, apex acute to obtuse; lateral veins hidden, invisible, free, endings without hydathodes on adaxial surface of lamina. Sori linear, deeply sunken in 2 grooves, 1 on each side of midrib, ± parallel to margin and midrib. Sporangia glabrous.
About seven species: Sri Lanka and China to Australia and Pacific islands; one species in China.
(Authors: Shannjye Moore (牟善杰); Barbara S. Parris)