Anglestem primrose willow exists in pond and swamp margins nearly throughout Florida, and blossom all year. There are nearly 30 species of Ludwigia in Florida (Wunderlin, 2003). In the US, Anglestem primrose willow is found throughout the southeast, and extends west to TX and north to PA (Kartesz, 1999).
View the herbarium specimen image from the University of Florida Herbarium Digital Imaging Projects.
For brief control information, see Efficacy of Herbicide Active Ingredients Against Aquatic Weeds by K. Langeland, M. Netherland, and W. Haller.