Perennial herbs with short scaly rhizomes. Fronds tufted at apices of rhizome branches, spirally coiled when young, more or less of one kind but those bearing sori with narrower segments, 1- to 4-pinnate, with the basal pinna on each side sometimes bearing another pinna near its base. Sori linear, along margins of fronds, protected by reflexed lamina edge. Sporangia homosporous. Indusia absent. Prothallus green, surface-living.

Contains 6 genera with a worldwide distribution.