Genera : 8
To Genus Directories:
Distribution: Cosmopolitan, but mainly in Australia and the Southern Hemisphere.
Economic Uses: Cultivated as an aquarium plant.
Defining Features of Interest: The family is an aquatic species and shows a dimorphism is the leaves between submerged and emergent forms.
Fossil Evidence:Fossil pollen from the Paleocene ans some questionable pollen from the Upper Cretaceous.