Nymphaea mexicana
Nymphaea lotus
banana water-lily, herbe au coeur, Mexican water lily, yellow or banana waterlily, yellow water-lily
Egyptian lotus (in part), white Egyptian lotus
unbranched, erect, cylindric;
stolons elongate, spongy, developing clusters of curved, fleshy, overwintering roots resembling tiny bananas at terminal nodes.
branched or unbranched, erect, ovoid;
stolons slender.
blade abaxially purplish with dark flecks, adaxially green, often with brown mottling, ovate to elliptic or nearly orbiculate, 7-18(-27) × 7-14(-18) cm, margins entire or sinuate;
venation radiate and impressed centrally, without weblike pattern, principal veins 11-22;
surfaces glabrous.
blade abaxially purplish, adaxially green, nearly orbiculate, to ca. 3 × 3 dm, margins spinose-dentate;
venation radiate and prominent centrally, without weblike pattern, principal veins ca. 15;
surfaces abaxially sparsely to densely puberulent.
floating or emersed, 6-11 cm diam., opening and closing diurnally, only sepals and outermost petals in distinct whorls of 4;
sepals uniformly yellowish green, often red-tinted, evidently veined, lines of insertion on receptacle often slightly prominent;
petals 12-30, yellow;
stamens ca. 50-60, yellow, connective appendage minute or absent;
filaments widest below middle, longer than anthers;
pistil 7-10-locular, appendages at margin of stigmatic disk oblong-tapered, to 4.5 mm.
emersed, 12-25 cm diam., opening nocturnally, many flowers not closing until late morning, only sepals and outermost petals in distinct whorls of 4;
sepals abaxially uniformly green, prominently veined, lines of insertion on receptacle not prominent;
petals 16-20, white;
stamens ca. 75, yellow, outer with connective appendage projecting less than 2 mm beyond anther;
filaments widest below middle, slightly shorter to longer than anthers;
pistil ca. 20(-30)-locular, appendages at margin of stigmatic disk linear, 6-12 mm.
globose, ca. 5 × 5 mm, uniformly covered with hairlike papillae 100-220 µm. 2n = 56.
ellipsoid, 1.4-1.8 × 0.9-1.2 mm, ca. 1.5-1.6 times as long as broad, with longitudinal ridges bearing papillae 20-150 µm.
Nymphaea mexicana
Nymphaea lotus
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.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
LA Plants
WildflowerSearch
iNaturalist
USDA Plants Database
