Mostly epiphytic, rarely terrestrial perennials, with a fleshy, creeping, scaly rhizome. Leaves all similar, pinnatifid or pinnatisect with segments confluent at base; veins forked or otherwise branched, usually anastomosing evenly into areoles (loops) with free endings inside loops. Sori terminal or almost so on veins, arranged in 1 (-3) rows on each side of the midrib, large, round or rarely oblong, yellow when ripe; indusium 0.