Annual. Rhizome very short, erect, covered with scales or hairs, roots abundant. Fronds tufted, delicate, glabrous (rarely slightly pubescent), ephemeral. Lamina deeply lobed to 4-pinnate, membranous, veins forked and free. Sporangia clustered in bands along veins, without indusium or any other protection; spores tetrahedral. Gametophyte annual or perennial.
7 species through tropical and temperate regions world-wide; 1 in Australia.