Rhizome creeping, hollow, ant-inhabited, in Australia eventually forming a large tangled clump, scaly (in Australia); scales peltate, round, centrally clathrate; naked rhizomes usually densely set with often rigid spines. Fronds monomorphic or subdimorphic. Stipes present or absent, articulated to a short usually distinct phyllopodium sometimes set on flask-like swellings of the rhizome. Lamina simple, lobed or deeply pinnatifid, or fertile part 2-pinnatifid, leaving a narrow wing on either side of pinna midrib, herbaceous to subcoriaceous, glabrous; marginal lobes usually broadly rounded, sometimes acute; veins anastomosing, a complex network with included free veins. Sori round to elliptic, in Australia superficial, sometimes impressed into lamina; paraphyses absent in Australia. Spores colourless or yellowish; exospore smooth; perispore variously ornamented.
Rhizome not scaly; Sori on distinct small lobes