Nymphaea  is a genus of hardy and tender aquatic plants in the family Nymphaeaceae  The genus has a cosmopolitan distribution  Many species are cultivated as ornamental plants  and many cultivars have been bred  Some taxa occur as introduced species where they are not native  and some are weeds  Plants of the genus are known commonly as water lilies The genus name is from the Greek νυμφαια, nymphaia and the Latin nymphaea  which mean "water lily" and were inspired by the nymphs of Greek and Latin mythology