Classification
 Nomenclature
Scientific Name:
Nymphaeales Salisb. ex Bercht. & J.Presl, Prir. Rostlin 270 (1820)
Synonymy:
  • = Hydatellales
 Description
Aquatic or sub-aquatic herbs; rhizomatous. Dicotylar; hypogeal germination. Arrangement of floral organs in whorls or irregular. Primary stem with ± scattered vascular bundles; vascular cambium absent; vascular bundles lacking associated sclerenchyma; S-type sieve element-plastids present; aerenchyma present. Stomata anomocytic, hydathodes present. Anthers basifixed, tetrasporangiate and dithecal with longitudinal slits, endothecium present; pollen monocolpate or monoaperturate (Nymphaea), exine tectate-columellate. Carpels 1–many, apocarpic or syncarpic; ovules anatropous (rarely orthotropous), crassinucellate; embryo sac 4-nucleate, maternal perisperm abundant, a diploid few-celled haustorial endosperm. Seeds with thickened exotesta cells, operculate.
 Taxonomy
The Nymphaeales is an order of three families with about 90 species in eight genera, Barclaya, Brasenia, Euryale, Cabomba, Nuphar, Nymphaea (incl. Ondinea), Trithuria, and Victoria. Although an early angiosperm lineage, most species display morphology in common with other plant groups of aquatic life-style. Cabombaceae and Nymphaeaceae in particular are macrophytes and have prominent specialised air-canals in vegetative parts and floating leaves on long petioles. The Hydatellaceae, however, differ considerably in that they are minute tufts with non-petiolate linear leaves with most species inhabiting ephemeral pools and wetlands. Characters shared (synapomorphies) by the three families include unusual embryological features, such as abundant maternal perisperm, a diploid few-celled haustorial endosperm, and a 4-nucleate embryo sac. Cabombaceae and Hydatellaceae share apocarpy and post-genital carpel closure, and Cabombaceae and Nymphaeaceae share solitary bisexual flowers, an undifferentiated perianth of tepals (Warner et al. 2009) and stellate parenchyma cells with crystals (astrosclereids).

The Nymphaeales are one of the first diverging branches of the flowering plant phylogeny, part of the ANA grade (Amborellales, Nymphaeales, Austrobaileyales). The order of these early lineages, however, is disputed (Borsch et al. 2003; Soltis et al. 2011; Drew et al. 2014; Goremykin et al. 2013, 2015; Gruenstaeudl et al. 2017). The oldest flowering plant fossil is identified as belonging to the Nymphaeales dating to the early Cretaceous, 115–125 Mya (Friis et al. 2001).
 Key
1Plants minute, with simple non-petiolate linear leaves; perianth absent, instead with hyaline bractsHydatellaceae
Plants not minute, with broad petiolate leaves, simple or divided; perianth petaloid2
2Floating leaves lobed or non-lobed, when lobed sagittate or hastate; perianth with six tepals in two trimerous whorls; gynoecium apocarpicCabombaceae
Emergent or floating leaves lobed, cordate; perianth with numerous tepals not in two trimerous whorls; gynoecium syncarpic or partially freeNymphaeaceae
 Distribution
Almost cosmopolitan, temperate and tropical.
 Biostatus
Indigenous (Non-endemic)
Number of species in New Zealand within Nymphaeales Salisb. ex Bercht. & J.Presl
CategoryNumber
Indigenous (Endemic)1
Exotic: Fully Naturalised4
Exotic: Casual1
Total6
 Bibliography
Berchtold, F.W., von; Presl, J.S. 1820: O přirozenosti Rostlin. Krause, Prague.
Borsch, T.; Hilu, K.W.; Quandt, D.; Wilde, V.; Neinhuis, C.; Barthlott, W. 2003: Non-coding plastid trnT-TrnF sequences reveal a well resolved phylogeny of basal angiosperms. Journal of Evolutionary Biology 16: 558–576.
Cronquist, A. 1988: The evolution and classification of flowering plants. The New York Botanic Gardens, New York.
Drew, B.T.; Ruhfel, B.R.; Smith, S.A.; Moore, M.J.; Briggs, B.G.; Gitzendanner, M.A.; Soltis, P.S.; Soltis, D.E. 2014: Another look at the root of the angiosperms reveals a familiar tale. Systematic Biology 63(3): 368–382.
Friis, E.M.; Pedersen, K.R.; Crane, P.R. 2001: Fossil evidence of water lilies (Nymphaeaceae) in the Early Cretaceous. Nature 410: 357–360.
Goremykin, V.V.; Nikiforova, S.V.; Biggs, P.J.; Zhong, B.; Delange, P.; Martin, W.; Woetzel, S.; Atherton, R.A.; McLenachan, P.A.; Lockhart, P.J. 2013: The evolutionary root of flowering plants. Systematic Biology 62: 50–61.
Goremykin, V.V.; Nikiforova, S.V.; Cavalieri, D.; Pindo, M.; Lockhart, P.J. 2015: The root of flowering plants and total evidence. Systematic Biology 64: 879–891.
Gruenstaeudl, M.; Nauheimer, L.; Borsch, T. 2017: Plastid genome structure and phylogenomics of Nymphaeales: conserved gene order and new insights in relationships. Plant Systematics and Evolution 303: 1251–1270.
Mabberley, D.J. 2008: Mabberley's plant book, a portable dictionary of plants, their classification and uses. Edition 3. Cambridge University Press.
Soltis, D.E; Smith, S.A.; Cellinese, N.; Wurdack, K.J.; Tank, D.C.; Brockington, S.F.; Refulio–Rodriguez, N.F.; Walker, J.B.; Moore, M.J.; Carlsward, B.S.; Bell, C.D.; Latvis, M.; Crawley, S.; Black, C.; Diouf, D.; Xi, Z.; Rushworth, C.A.; Gitzendanner, M.A.; Sytsma, K.J.; Qiu, Y.L.; Hilu, K.W.; Davis, C.C.; Sanderson, M.J.; Beaman, R.S.; Olmstead, R.G.; Judd, W.S.; Donoghue, M.J.; Soltis, P.S. 2011: Angiosperm phylogeny: 17 genes, 640 taxa. American Journal of Botany 98: 704–730.
Warner, K.A.; Rudall, P.J.; Frohlich, M.W. 2009: Environmental control of sepalness and petalness in perianth organs of waterlilies: a new Mosaic Theory for the evolutionary origin of a differentiated perianth. Journal of Experimental Botany 60(12): 3559–3574.