The species is pantropical, occurring on all continents except Antarctica (Adebayo et al. 2011). The origin of Pistia stratiotes is not clear (Parsons and Cuthbertson 2001). It is thought to have originated from Africa or South America (Langeland and Burks 1999). Fossil records for this species can be found around the globe (Stoddard 1989). Ancient Egyptian hieroglyphics depict the plant and Greek botanists Dioscorides and Theophrastus described the plant floating on the Nile River more than 2,000 years ago, indicating African origin (Stoddard 1989). Pistia stratiotes in Brazil and Argentina host a large number of co-evolved specialist insect herbivores suggesting a South American origin (Center et al. 2002). In North America, both John and William Bartram described P. stratiotes as early as 1765 and 1773, respectively, along the St. Johns River in Florida, up to 300 river km upstream of the ocean inlet where any ballast material would likely have been deposited from trans-oceanic ships (Bartram and Harper 1942; Bartram and Harper 1943). Since plants were found so far upstream from known seaports, a rationale for Florida nativity has been suggested (Evans 2013). Late Pleistocene/early Holocene fossil records for this species in Florida lend support for this contention (Stoddard 1989; Evans 2013). Nonindigenous Occurrences: Pistia stratiotes was first reported in Australia in 1887 (Parsons and Cuthbertson 2001). Pistia stratiotes had established in Volta Lake, Ghana before the 1960s (Hall and Okali 1974). It has established in the Erft River in Germany in 2008 (Hussner et al. 2014).
Pistia stratiotes has been reported in:
Alabama- Lower Conecuh, Lower Coosa, and Upper Alabama drainages (University of Alabama Biodiversity and Systematics 2007; Center for Invasive Species and Ecosystem Health 2015);
Arizona (Ramey 2001);
California- Laguna-San Diego Coastal, Salton Sea, Santa Ana (Regents of the University of California 2015), Lower Colorado (Potter and Dean 2015), Lower Sacramento (Fred Hrusa, CDFA, pers. comm.), Central California Coastal, Northern California Coastal, Ventura-San Gabriel Coastal (Calflora 2015), and San Joaquin (Consortium of California Herbaria 2014) drainages;
Colorado- Little Turkey Creek in the Upper Arkansas drainage (University of Colorado Museum of Natural History 2007);
Connecticut- Housatonic, Lower Connecticut, Shetucket (University of Connecticut 2011), and Quinnipiac (Yale University Peabody Museum 2009) drainages;
Delaware (Aquatic Resources Education Center 1995; Ramey 2001);
Florida- and occurs in the Econfina-Steinhatchee (University of Alabama Biodiversity and Systematics 2007), Ochlockonee (Anderson 2001; GISD 2005), and Florida Panhandle Coastal (Center for Invasive Species and Ecosystem Health 2015) drainages, and in Baker County (Aurand 1982);
Georgia (GISD 2005);
Hawaii- the islands of Kuaai, Molokai (Mehrhoff 1996), Maui (Wagner et al. 2005), and Oahu (Naturalis Biodiversity Center 2013);
Idaho- Bruneau River in Middle Snake-Boise drainage (Thomas Woolf, IDA, pers. comm.);
Illinois- Chicago (Center for Invasive Species and Ecosystem Health 2015), Des Plaines (Adam et al. 2001), Little Wabash (University of Connecticut 2011), and Upper Fox (Adam et al. 2004) drainages;
Kansas- Independence-Sugar (Jason Goeckler, KDWP, pers. comm.), Lower Cottonwood (Freeman 2000), and Middle Neosho (University of Kansas Biodiversity Institute 2008) drainages;
Louisiana- Lake Pontchartrain (Thomas and Allen 1993), Atchafalaya-Vermillion (University of Alabama Biodiversity and Systematics 2007), Big Cypress-Sulphur (Louisiana State University Herbarium 2010), Central Louisiana Coastal (Hodgson 2015), Calcasieu-Mermentau (Valentine 1976), and Lake Maurepas (Thomas M. Pullen Herbarium 2005) drainages, and Lincoln, Ouachita, and St. Tammany Parishes (Thomas and Allen 1993);
Michigan- Detroit, Huron, Lake Erie, Ottawa-Stony, and Upper Grand drainages (Michigan State University 2015; Adebayo et al. 2011;MacIsaac et al. 2016);
Minnesota - Buffalo-Whitewater, Twin Cities (Center for Invasive Species and Ecosystem Health 2015), Rush-Vermillion drainages (Balgie et al. 2010), and Lake Winona (Cochran et al. 2006);
Mississippi - Lower Big Black, Middle Pearl-Strong (Mississippi Museum of Natural Science 2016), Lower Yazoo (Sam Faulkner, Delta State Univ., pers. comm.), Mississippi Coastal (Center for Invasive Species and Ecosystem Health 2015), and Tibbee (Madsen 2010) drainages;
Missouri - LaBarque Creek in Meramec drainage (Missouri Botanical Garden 2007);
New Jersey (Cochran et al. 2006);
New York - Bull and Ellicott Creeks in Niagara drainage (Mike Goehle, USFWS, pers. comm.), and Westbury Pond in Southern Long Island drainage (Conover 2007);
North Carolina - Burnt Mill Creek pond in the Ann McCrary Park section in Northeast Cape Fear drainage (Diana Rashash, NC Coop. Ext. Service, NCSU, pers. comm.);
Ohio - Metzger Marsh of western Lake Erie in Cedar-Portage drainage (Wilcox and Whillans 1999), and Olentangy River of Fawcett in Upper Scioto drainage (University of Connecticut 2011);
Ontario- Found in the Detroit River and Lake St. Clair (Adebayo et al. 2011; MacIsaac et al. 2016);
Rhode Island- James V. Turner Reservoir of East Providence in Narragansett drainage, and Chipuxet River at Taylors Landing of West Kingston in Pawcatuck-Wood drainage (Lisa Gould, RI Natural History Survey, pers. comm.);
South Carolina (Ramey 2001);
Texas (Ramey 2001);
Wisconsin- Buffalo-Whitewater (Center for Invasive Species and Ecosystem Health 2015), Castle Rock (WI DNR 2010), La Crosse-Pine (Roe 2015), and Upper Rock (Susan Graham, WI DNR, pers. comm.) drainages.