1 | Sporangia in each group along the veins near margins of leaflets; veins free. |
1' | Sporangia in each group united laterally to form a small circle, the circular groups scattered over the surface; veins anastomosing |
2 | Sporangia in each group united laterally |
2' | Sporangia in each group almost free. |
3 | Fronds bipinnate; sporangia in each group commonly 8-12, less often to 20 |
3' | Fronds simply pinnate; sporangia in each group much more numerous. |