A family of flowering plants. Members of this family are commonly called water lilies and live in freshwater areas in temperate and tropical climates around the world. The family contains eight genera. There are about 70 species of water lilies around the world. The genus Nymphaea contains about 35 species across the Northern Hemisphere. The genus Victoria contains two species of giant water lilies and can be found in South America[1]. Water lilies are rooted in soil in bodies of water, with leaves and flowers floating on the water surface. The leaves are round, with a radial notch in Nymphaea and Nuphar, but fully circular in Victoria.

Water lilies are divided into two main categories: hardy and tropical. Hardy water lilies bloom only during the day, but tropical water lilies can bloom either during the day or at night, and are the only group to contain blue-flowered plants.

from: Wikipedia