Native to eastern North America, and found throughout the United States and Canada north to Alaska, due in part to its common sale and use for ornamental garden ponds. It is a listed noxious weed in some states due to its rapid growth and ability to cover wide areas of water.
A true aquatic plant, growing on the surface of water with long tubers extending vertically below. Reproduction is from seeds, and plants also spread rapidly with growth from their rhizomes. Flowers have a sweet scent in this species. Plants are tolerant of a wide range of water types, from acidic to alkaline, from still to running.
The floating leaves are nearly perfectly round with radiate venation, growing to over 6 inches in diameter. The leaves are thin and flat and lay on the water surface. Flowers are large and showy, white to pink to reddish in color, and with a sweet fragrance. The rhizomes are branched and large, being about an inch in diameter in cross-section, covered with short black hairs, and creeping along the soil surface below water.
Characteristicts Important to Control:
Physical removal is unlikely to be successful due to the extensive system of rhizomes well underwater. A systemic herbicide labeled for aquatic uses will be needed to be successful in killing the underwater plant parts.