Description from Flora of China
Herbs perennial. Rhizomes erect, ascending, or repent, branched or unbranched. Leaves mostly floating; leaf blade venation primarily palmate, base cordate to sagittate, margin entire to dentate, sometimes slightly peltate. Flowers floating or emersed, perianth spreading. Sepals 4, greenish, not petaloid, inserted at base of ovary, sometimes persistent. Petals 8 to many, large and showy, inserted on surface of ovary, often grading into stamens. Stamens shorter than sepals and petals, inserted on lateral surface of ovary; filament linear to ovate or obovate; anther connective appendaged or unappendaged. Carpels partially or completely united. Style absent or modified into abaxially projecting carpellary appendages. Stigma sessile, radiate on cup-shaped stigmatic disc rimmed by carpellary appendages. Fruit irregularly dehiscent. Seeds globose, ovoid, or ellipsoid, smooth or longitudinal ridges pubescent, arillate.
Many species of the genus Nymphaea are cultivated as ornamentals. In China, in addition to the native species, both Nymphaea mexicana Zuccarini and N. alba Linnaeus var. rubra Lönnroth are cultivated.
About 50 species: widespread in temperate and tropical regions; five species in China.