Nymphaea [nɪmˈfɛa] 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, or waterlilies in the United Kingdom. The genus name is from the Greek νυμφαία, nymphaia and the Latin nymphaea, which mean "water lily" and were inspired by the nymphs of Greek and Latin mythology.
|Nymphaea 'Peach Glow'|
About 36 species, see text
Water lilies are aquatic rhizomatous perennial herbs, sometimes with stolons, as well. The leaves grow from the rhizome on long petioles. Most of them float on the surface of the water. The blades have smooth or spine-toothed edges, and they can be rounded or pointed. The flowers rise out of the water or float on the surface, opening during the day or at night. Many species of Nymphaea display protogynous flowering. The temporal separation of these female and male phases is physically reinforced by flower opening and closing, so the first flower opening displays female pistil and then closes at the end of the female phase, and reopens with male stamens. Each has at least eight petals in shades of white, pink, blue, or yellow. Many stamens are at the center. Water lily flowers are entomophilous, meaning they are pollinated by insects, often beetles. The fruit is berry-like and borne on a curving or coiling peduncle.
Water lilies are not only decorative, but also provide useful shade which helps reduce the growth of algae in ponds and lakes. Many of the water lilies familiar in water gardening are hybrids and cultivars. These cultivars have gained the Royal Horticultural Society's Award of Garden Merit:
Water lilies have several edible parts. The young leaves and unopened flower buds can be boiled and served as a vegetable. The seeds, high in starch, protein, and oil, may be popped, parched, or ground into flour. Potato-like tubers can be collected from the species N. tuberosa.
This is one of several genera of plants known commonly as lotuses. It is not related to the legume genus Lotus or the Chinese and Indian lotuses of genus Nelumbo. It is closely related to Nuphar lotuses, however. In Nymphaea, the petals are much larger than the sepals, whereas in Nuphar, the petals are much smaller. The process of fruit maturation also differs, with Nymphaea fruit sinking below the water level immediately after the flower closes, and Nuphar fruit remaining above the surface.
Subdivisions of genus Nymphaea:
- section Chamaenymphaea
- section Nymphaea
- section Xanthantha
- Nymphaea alba – white water lily (type species)
- Nymphaea amazonum – Amazon water lily
- Nymphaea ampla – dotleaf water lily
- Nymphaea blanda
- Nymphaea caerulea – blue Egyptian lotus
- Nymphaea calliantha
- Nymphaea candida
- Nymphaea capensis – Cape blue waterlily
- Nymphaea colorata
- Nymphaea conardii – roundleaf water lily
- Nymphaea elegans – tropical royalblue water lily
- Nymphaea fennica
- Nymphaea flavovirens
- Nymphaea gardneriana
- Nymphaea gigantea – giant water lily
- Nymphaea glandulifera– sleeping beauty water lily
- Nymphaea heudelotii
- Nymphaea jamesoniana – James' water lily
- Nymphaea leibergii – Leiberg's water lily
- Nymphaea lotus – Egyptian white water lily
- Nymphaea lotus f. thermalis
- Nymphaea macrosperma
- Nymphaea mexicana – yellow water lily
- Nymphaea miami - called as Miami Rose
- Nymphaea micrantha
- Nymphaea nouchali – blue lotus
- Nymphaea odorata – fragrant water lily
- Nymphaea pubescens – hairy water lily
- Nymphaea rubra – India red water lily
- Nymphaea rudgeana
- Nymphaea stuhlmannii
- Nymphaea sulfurea
- Nymphaea tetragona – pygmy water lily
- Nymphaea thermarum
- Nymphaea violacea
The ancient Egyptians revered the Nile water lilies, which were known as lotuses. The lotus motif is a frequent feature of temple column architecture. In Egypt, the lotus, rising from the bottom mud to unfold its petals to the sun, suggested the glory of the sun's own emergence from the primaeval slime. It was a metaphor of creation. It was a symbol of the fertility gods and goddesses as well as a symbol of the upper Nile as the giver of life.
The flowers of the blue Egyptian water lily (N. caerulea) open in the morning and then sink beneath the water at dusk, while those of the white water lily (N. lotus) open at night and close in the morning. Egyptians found this symbolic of the separation of deities and of death and the afterlife. Remains of both flowers have been found in the burial tomb of Ramesses II.
A Syrian terra-cotta plaque from the 14th-13th centuries BC shows the goddess Asherah holding two lotus blossoms. An ivory panel from the 9th-8th centuries BC shows the god Horus seated on a lotus blossom, flanked by two cherubs.
Water lilies are also used as ritual narcotics. This topic "was the subject of a lecture by William Emboden given at Nash Hall of the Harvard Botanical Museum on the morning of April 6, 1979".
Water lillies were a major food source for Indigenous Australians, with the flowers and stems eaten raw while the roots and seedpods were cooked either on an open fire or in a ground oven 
- Albert de Lestang, propagator and seed collector
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