Hydatellaceae: A historical review of systematics and ecology

Abstract

This paper presents an overview of the history of taxonomic and evolutionary studies of species currently assigned to the family Hydatellaceae, including a comparison of the ecology of species from India, Australia and New Zealand. We review previous ideas on the relationships of Hydatellaceae with the monocot family Centrolepidaceae and their current placement within the early-divergent angiosperm order Nymphaeales. An earlier hypothesis is discussed regarding the putative close relationships between Hydatellaceae and the Lower Cretaceous fossil genus Archaefructus. We hope that this review will stimulate field botanists in various countries for new records of these highly unusual and interesting plants.