Hottonia

Hottonia is a genus of aquatic flowering plants in the family Primulaceae. It comprises two species:

The two species differ markedly in the size of the flowers, which are showy in the Eurasian H. palustris but much smaller in the North American H. inflata, and in the thickness of the stem, which is swollen in H. inflata but not in H. palustris. The two species also differ in their breeding system: H. palustris is heterostylous, whereas H. inflata is not.