| 1 | Fronds simple and entire or with somewhat undulate edges. |
| 1' | Fronds pinnately lobed to bipinnately lobed. |
| 2 | Sori round or obliquely elliptical, separate |
| 2' | Sori elongate parallel to costa and edge, or confluent near apex of frond. |
| 3 | Sori in grooves between margin and costa. |
| 3' | Sori more or less confluent near apex, not in grooves |
| 4 | Fronds almost terete apart from widened apical fertile part |
| 4' | Fronds of about uniform width throughout |
| 5 | One vein (sometimes forked) and one sorus on each lamina-lobe. |
| 5' | Veins in lobes pinnately branched, each lobe with more than one sorus. |
| 6 | Fertile lobes flat. |
| 6' | Fertile lobes partly reflexed, protecting the sori. |
| 7 | Sori superficial |
| 7' | Sori deeply sunk in submarginal pockets |
| 8 | Lobes thin, only basiscopic margin reflexed |
| 8' | Lobes coriaceous, both margins reflexed towards apex and enclosing the sorus |
| 9 | Sori superficial, or sunk in cavities perpendicular to the surface. |
| 9' | Sori deeply sunk in submarginal pockets not perpendicular to the surface |
