15. Parahemionitis Panigrahi, Indian Fern J. 9: 244. 1993.
泽泻蕨属 ze xie jue shu
Authors: Zhang Gangmin & Tom A. Ranker
Plants terrestrial. Rhizomes erect, short, with small, fluffy scales and long, jointed hairs, dictyostelic. Fronds somewhat dimorphic, clustered; stipe chestnut-colored or purple-black, densely scaly and hairy as on rhizomes; stipe of fertile frond usually 1-3 × length of stipe of sterile frond; lamina simple, ovate, oblong-ovate, or hastate, herbaceous, brown and sparsely covered with small subulate scales abaxially, glabrous adaxially, base strongly cordate, apex obtuse or rounded. Veins anastomosing, areoles numerous, densely arranged, elongate hexagonal. Indusia absent. Sori following course of veins, confluent throughout abaxial surface when mature. Spores globose-tetrahedral, cristate. x = 30.
One species: tropical Asia.
Parahemionitis cordata is often included in the genus Hemionitis Linnaeus, but it has subulate scales instead of hairs abaxially, differing from Hemionitis species in the Americas. As well, P. cordata has hairs on the adaxial lamina surface with small fingerlike projections on the non-apical cells that are not found on the hairs of true Hemionitis. Panigrahi thought it reasonable to put the Asian species into another genus, Parahemionitis.