American White Water-lily (Nymphaea odorata) native - 7/04/08 Finger Lakes, NY

flower petals are thick and pointed
leaves roundish with deep notch or cut almost to center
usually flowers only from early morning until noon
may be pink

do not confuse with Lotus which also may be pink

https://www.wildflower.org/plants/result.php?id_plant=nyod
https://www.wildflower.org/gallery/species.php?id_plant=nyod
https://plants.usda.gov/core/profile?symbol=NYOD&photoID=nyod_003_ahp.tif
http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=c547