Small, mainly terrestrial ferns. Rhizome creeping or sometimes short and almost erect, densely covered with narrow scales. Stipe often with a few scales near base. Frond simple to pinnately divided, pinnae variously shaped; rachises deeply grooved; thickened lower margin of pinnae decurrent on edge of rachis-groove. Sori near margins, discrete or continuous, protected by membranous indusium which opens towards margin; spores are tetrahedral or bilateral. Gametophyte cordate.
About 6 genera world-wide, mostly in tropics; 1 in Australia.