THE WATER LILY FAMILY (Nymphaeaceae)

Nymphaeaceae is a family of flowering plants that live as rhizomatous aquatic herbs in temperate and tropical climates around the world. Water lilies are rooted in soil in bodies of water, with leaves and flowers floating on the surface. Their large flowers with multiple unspecialized parts are considered to represent the floral pattern of the earliest flowering plants (basal angiosperms). The family is further characterized by scattered vascular bundles (veins) in the stems (not the regular arrangement of evolutionarily more advanced flowering plants) and of the frequent presence of hairs producing mucilage (slime). Horticulturally water lilies have been hybridized for temperate gardens since the nineteenth century, and the hybrids are divided into three groups: hardy, night-blooming tropical, and day-blooming tropical.

The leaves are round, with a radial notch in Nymphaea and Nuphar, but fully circular in Victoria. They may exist as underwater and/or floating forms. All the vegetative parts, leaves and stems alike, possess air canals and usually have simple hairs producing mucilage (slime).

Flowers are solitary, bisexual, radial, with a long pedicel and usually floating or raised above the surface of the water. Genera with more floral parts, (Nuphar, Nymphaea and Victoria), are pollinated by beetles while genera with fewer parts are pollinated by flies or bees, or are self- or wind-pollinated. There are no distinct petals and sepals as is characteristic in most higher plants. The form of the numerous, usually petal-like and spirally arranged tepals may change gradually into that of the stamens towards the middle of the flower. Stamens and carpels vary in number from 3 to numerous and the fruit is an aggregate of nuts, a berry, or an irregularly dehiscent fleshy capsule.

(source: Wikipedia)