Nymphaea
Nymphaea /nɪmˈfiːə/ 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,[2] and some are weeds.[3] Plants of the genus are known commonly as water lilies,[2][4] 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.[2]
Water lilies are aquatic rhizomatous herbaceous perennials, sometimes with stolons, as well. The stem is angular and erect. The leaves grow from the rhizome on long petioles(stalk that attaches the leaf blade to the stem). Floating round leaves of waterlily grow up to 300 mm (12 in) across. The disc shaped leaves are notched and split to the stem in a V-shape at the centre, and are often purple underneath. 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.[2] 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.[5] Each has at least eight petals in shades of white, pink, blue, or yellow. Many stamens are at the center.[2] Water lily flowers are entomophilous, meaning they are pollinated by insects, often beetles.[2] The fruit is berry-like and borne on a curving or coiling peduncle.[2]Plant reproduce by root tubers and seeds.
Water lilies are not only decorative, but also provide useful shade which helps reduce the growth of algae in ponds and lakes.[6] 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:
All water lilies are poisonous and contain an alkaloid called nupharin in almost all of their parts, with the exception of the seeds and in some species the tubers.
The European species contain large amounts of nupharin, and are considered inedible. The amount of nupharin in the leaves and stalks appears to vary seasonally in European species.
In India it has mostly been eaten as a famine food or as a medicinal (both cooked), but in one area the dried rhizomes were pounded into a sort of bread, and the tubers are often eaten in the floodplains.
