Abh. Math.-Phys. Cl. Königl. Bayer. Akad. Wiss. 1: 365. 1832
Illustrator: John Myers
Phenology: Flowering spring–fall, mainly summer farther north.
Habitat: Outer coastal plain in alkaline lakes, ponds, warm springs, pools in marshes, sloughs, sluggish streams, ditches, and canals
Elevation: 0-1100 m
Ala., Ariz., Calif., Fla., Ga., La., Miss., N.C., Okla., S.C., Tex., ne, c Mexico.
Nymphaea mexicana is probably introduced in most inland sites and in California, where it is considered a problematic weed in waterways; it is not common in most states except Florida. The distribution of this species is similar to that of the winter distribution of canvasback ducks, for which the bananalike tubers are an important food (J. E. Cely 1979). This species forms natural hybrids with N. odorata; the hybrids have been named N. ×thiona D. B. Ward (D. B. Ward 1977). Except for stem characteristics, which resemble one or the other parent, and their added vigor, the hybrids are generally intermediate in morphology. They are completely sterile; however, hybrids with the stolon-bearing habit of N. mexicana can form extensive clones and, although somewhat larger in stature than N. mexicana, they closely resemble that less agressive parent and could easily be mistaken for it. Some of the introductions, such as in southeastern Nevada and north-central Kentucky, are clearly this hybrid.