Terrestrial ferns. Rhizome or caudex short, oblique, erect or shortly creeping, dictyostelic, clothed with non-clathrate scales which are entire or bearing marginal teeth composed of 2 cells which may separate at their apices. Stipes often robust, with 2 vascular strands joined higher up into a U-shaped bundle. Rhachises mostly papillate in the groove on the upper surface and scaly or hairy on the lower surface. Fronds uniform or dimorphic, mostly thin. Costae grooved. Lamina simple to decompound. Veins free or rarely anastomosing especially towards the margin, lacking free included veinlets. Sori dorsal, linear to oblong, usually elongated along the veins, sometimes ± curved and inflated, sometimes reniform or rarely small and round; the basal acroscopic sori often double (i.e. occurring on both sides of the veinlet). Indusium narrow, elongated along the veinlets, sometimes J-shaped to horseshoe-shaped, almost round or reniform, rarely absent. Sporangia globose; the annulus including 12–20 (mostly 16) thick-walled cells; pedicel slender. Spores bilateral, with perispore. c. 23 gen., cosmop.