Prothallus usually perennial and tuberous. Sporophyte annual or (not in Australia) perennial; rhizome rudimentary, bearing ferruginous scales grading into hairs. Fronds small, tufted. Lamina in full development 3-pinnate with decurrent ultimate segments that are membranaceous or thinly herbaceous, incised, glabrous or slightly hairy; veins forked, free. Sori exindusiate, seriate along, and forking with, the veins, without paraphyses; spores tetrahedral, with reticulate ornamentation.
Sporangia unprotected, in series along veins, without paraphyses; spores striate. Rhizome ill-developed, paleate to hairy. Fronds small, apparently annual; lamina often tripinnate, glab. to somewhat hairy; veins free, forked. Prothallus apparently perennial. A few rather ill-defined spp. of wide distribution.
Sori on lower surface, spreading a little along the veins