Herbs, to 50 cm; stolons to 45 cm. Leaves: petioles 1.5--40 cm × 0.9--9 mm, sheathing base to 8.5 cm; blade broadly ovate to orbiculate, 1.4--11.9 × 0.9--10.6 cm, veins 5--9. Inflorescences with 1--6 flowers, proliferating with stolons, leaves; peduncles to 30 cm × 1.5--6 mm; bracts elliptic, 2--4.5 × 0.4--1 cm, apex obtuse; pedicels spreading, 3.5--17.5 cm × 1.5--6 mm. Flowers ca. 6.5 cm wide; sepals 13--28 × 7--13 mm; petals spreading, pale yellow to white with yellow base, 2.3--2.6 × 3.8--4.1 cm; stamens 20--25; staminodes 20+; pistils 5--8, 10 mm. Fruits 10--14.5 × 2--3.5 mm; beak 3.5--5.5 mm. Seeds ca. 1 mm, sparsely glandular-pubescent, glandular trichomes 0.15 mm, 150--200 m m apart, not present on every epidermal cell of seed coat.

Flowering summer. Margins of lakes and wet ditches; 0--100 m; introduced; Fla., Tex.; Central America; South America.

Hydrocleys nymphoides is cultivated, either in aquaria or in pools and ponds (D. S. Correll and M. C. Johnston 1970; R. K. Godfrey and J. W. Wooten 1979). The species apparently persists following cultivation or dumping of aquaria.

OTHER REFERENCES

Correll, D. S. and M. C. Johnston. 1970. Manual of the Vascular Plants of Texas. Renner, Tex. Godfrey, R. K. and J. W. Wooten. 1979. Aquatic and Wetland Plants of Southeastern United States: Monocotyledons. Athens, Ga. Muenscher, W. C. 1944. Aquatic Plants of the United States. Ithaca, N.Y. Thieret, J. W. 1972. Aquatic and marsh plants of Louisiana: A checklist. J. Louisiana Soc. Hort. Res. 13: 1--45.