MARATTIACEAE

1Sporangia 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
2Sporangia in each group united laterally
2'Sporangia in each group almost free.
3Fronds bipinnate; sporangia in each group commonly 8-12, less often to 20
3'Fronds simply pinnate; sporangia in each group much more numerous.