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Nymphaeales is an order of flowering plants, consisting of three families of aquatic plants, the Hydatellaceae, the Cabombaceae, and the Nymphaeaceae (water lilies). It is one of the three orders of basal angiosperms, an early-diverging grade of flowering plants. At least 10 morphological characters unite the Nymphaeales.〔Peter F. Stevens. 2001 onwards. Angiosperm Phylogeny Website At: Missouri Botanical Garden Website. (see ''External links'' below).〕 Molecular synapomorphies are also known. The Plant List, created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden recognizes about 70 species in 11 genera within the order,〔The Plant List (website). 2010. (See ''External links'' below.)〕 but a phylogenetic study of the genus ''Nymphaea'' implies that the number of species could be more than 90. The difference in species numbers is due almost entirely to the difficulty of delineating species in the genus ''Nymphaea''. All of the species are rhizomatous aquatic herbs with a broad leaf base and large showy flowers. == Fossils == The fossil record consists especially of seeds, but also pollen, stems, leaves, and flowers. It extends back to the Cretaceous.〔(【引用サイトリンク】 Nymphaeales: Fossil Record )〕 The crown group of Nymphaeales has been estimated to be about 112 million years old. Some have suggested that this age might be too old. It is possible that the aquatic plant fossil ''Archaefructus'' belongs to this group. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Nymphaeales」の詳細全文を読む スポンサード リンク
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