| 1 | Fronds gemmiferous; free pinnae in 17-23 pairs, suboppositely arranged (sometimes alternately), usually basally asymmetric by the reduction of the basalmost basiscopic lobe. Sori present mostly along the primary areoles of the costules, although occasionally present along the primary areoles of the costae; indusia thin, membranous, and lax, undifferentiated, irregularly reflexed upon dehiscence of the sporangia |
| 1' | Fronds gemmiferous with scattered to numerous, articulated gemmae on the adaxial surface of the lamina or gemmiferous on the rhachis by the presence of one or two non-articulate scaly buds; free pinnae 7-16 pairs, alternately arranged, basally ± symmetric or strongly asymmetric by the reduction of several basalmost basiscopic lobes. Sori mostly confined to the primary areoles of the costules; indusia cartilaginous with a thickened basal flange and a membranous conduplicate margin |
| 2 | Gemmae numerous per frond, adaxial on the surface of the lamina, articulate; free pinnae in 7-12 pairs, basally strongly asymmetric by the reduction of several basalmost basiscopic lobes |
| 2' | Gemmae one or two per frond, abaxial along the rhachis, not articulate; free pinnae in 11-16 pairs, basally ± symmetric about the costae |
