[Wikipedia] Dispersal: The reason these plants are scattered all over the globe is because Ludwigia can be generated during all seasons just from fragments of stems or rhizomes. They can be broken as easily by wind, water flow or animals. Lugwigia Peploides have the ability to double their biomass from their broken particles between 15 and 90 days. This also allows this species to continue to thrive in habitat and regions where sexual reproduction cannot occur. (link added by Mary Ann Machi)

[Wikipedia] Australia, New Zealand, North & South America native: It is native to Australia, New Zealand, North America, and South America, but it can be found on many continents and spreads easily to become naturalized. It is well known as a troublesome aquatic noxious weed that invades water ecosystems and can clog waterways. (link added by Mary Ann Machi)

[Cal-IPC] Invasiveness: Ludwigia peploides (creeping water-primrose) is a perennial aquatic plant (family Onagraceae) that forms very dense, virtually impenetrable mats which restrict fishing and boat access. It also out competes native aquatic plants. Ludwigia peploides can be found throughout California in rice fields, ditches, ponds, slow moving streams, and along edges of lakes and reservoirs. There is some confusion as to which non-native species occur in California and more than one, yet unknown, species may be invasive. Cal-IPC Rating: High (link added by Mary Ann Machi)