12. Nymphaeaceae Salisbury
Water-lily Family
John. H. Wiersema & C. Barre Hellquist
Herbs , perennial, aquatic, rhizomatous; roots adventitious; air chambers conspicuous in vegetative portions of plant. Rhizomes branched or unbranched, erect or repent, tuberous-thickened, sometimes bearing stolons. Leaves arising directly from rhizome, alternate, floating, submersed, or emersed; stipules present or absent; petioles long. Leaf blade lanceolate to ovate or orbiculate, with basal sinus [peltate], margins entire to spinose-dentate. Inflorescences axillary or extra-axillary, flowers solitary. Flowers bisexual, protogynous [homogamous in some species of Nymphaea], diurnal or nocturnal, borne at or above water surface, occasionally submersed; peduncle long; involucre absent; perianth often persistent in fruit, hypogynous to perigynous [epigynous]; sepals usually (4-)5-12, distinct; petals numerous [rarely absent], often transitional to stamens; stamens numerous; filaments broad to slender; anthers dehiscing by longitudinal slits, with or without connective appendage; pistil 1, 3-35-carpellate and -locular; placentation laminar; ovules numerous per locule; stigma sessile, radiate on stigmatic disk. Fruits berrylike, indehiscent or irregularly dehiscent. Seeds several-numerous; aril present or absent; endosperm sparse; perisperm abundant; embryo minute; cotyledons 2, fleshy.
Genera 6 (including Barclaya), species ca. 50 (2 genera, 17 species in the flora): nearly worldwide.
Nymphaeaceae are insect-pollinated, often by beetles.
Formerly Nymphaeaceae often have been treated to include Cabombaceae and Nelumbonaceae, but these are now generally segregated.
SELECTED REFERENCES
Schneider, E. L. 1979. Pollination biology of the Nymphaeaceae. In: D. M. Caron, ed. 1979. Increasing Production of Agricultural Crops through Increased Insect Pollination: Proceedings of the IVth International Symposium on Pollination. College Park, Md. Pp. 419-429. [Maryland Agric. Exp. Sta. Special Misc. Publ. 1.] Wood, C. E. Jr. 1959. The genera of the Nymphaeaceae and Ceratophyllaceae in the southeastern United States. J. Arnold Arbor. 40: 94-112.
