Yellow water lily
Yellow water lily is native to Florida. It is a different species from the fragrant water lily. It sometimes occurs in other southern states (extirpated in Mississippi); but is considered a “state-level noxious weed” in California (Kartesz 1999).
In Florida, yellow water lily occasionally is found in ponds, lakes, streams and rivers of the peninsula and Wakulla county. It flowers in the spring and summer (Wunderlin, 2003).
For brief control information, see Efficacy of Herbicide Active Ingredients Against Aquatic Weeds (EDIS Pub #SS-AGR-44)