Xanthantha Species As accepted by Plants of the World Online; Nymphaea abhayana Nymphaea alba – white water lily Nymphaea alexii Nymphaea amazonum – Amazon water lily Nymphaea ampla – dotleaf water lily Nymphaea atrans Nymphaea belophylla Nymphaea × borealis Nymphaea candida Nymphaea carpentariae Nymphaea conardii – roundleaf water lily Nymphaea × daubenyana Nymphaea dimorpha Nymphaea divaricata Nymphaea elegans – tropical royalblue water lily Nymphaea elleniae Nymphaea gardneriana Nymphaea georginae Nymphaea gigantea – giant water lily Nymphaea glandulifera – sleeping beauty water lily Nymphaea gracilis Nymphaea guineensis Nymphaea hastifolia Nymphaea heudelotii Nymphaea immutabilis Nymphaea jacobsii Nymphaea jamesoniana – James' water lily Nymphaea kimberleyensis Nymphaea lasiophylla Nymphaea leibergii – Leiberg's water lily Nymphaea lingulata Nymphaea loriana Nymphaea lotus – Egyptian white water lily Nymphaea lukei Nymphaea macrosperma Nymphaea maculata Nymphaea malabarica Nymphaea manipurensis Nymphaea mexicana – yellow water lily Nymphaea micrantha Nymphaea noelae Nymphaea nouchali – blue lotus Nymphaea novogranatensis Nymphaea odorata – fragrant water lily Nymphaea ondinea Nymphaea oxypetala Nymphaea potamophila Nymphaea prolifera Nymphaea pubescens – hairy water lily Nymphaea pulchella Nymphaea × rosea Nymphaea rubra – India red water lily Nymphaea rudgeana Nymphaea siamensis Nymphaea stuhlmannii Nymphaea sulphurea Nymphaea × sundvikii Nymphaea tenuinervia Nymphaea tetragona – pygmy water lily Nymphaea thermarum Nymphaea × thiona Nymphaea vanildae Nymphaea vaporalis Nymphaea violacea Note; Nymphaea caerulea – blue Egyptian lotus - synonym of Nymphaea nouchali var. caerulea. Cultivation 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: 'Escarboucle' (orange-red) 'Gladstoniana' (double white flowers with prominent yellow stamens) 'Gonnère' (double white scented flowers) 'James Brydon;' (cupped rose-red flowers) 'Marliacea Chromatella' (pale yellow flowers) 'Pygmaea Helvola' (miniature, with cupped fragrant yellow flowers) Uses 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 some species, the rhizomes and tubers are eaten after boiling has neutralised the nupharin. The tubers of a number of Australian, Asian and African species are completely edible, during the dry season some consist almost entirely