This species of southeastern marshes (often with seasonal dryi8ng or breowsing) is known from se. Mo., and it might occur in Ky. as temporary or outllying waifs. There have been unverified reports from FULT by M. Medley and by R. Athey (M), but colls. have not been located. A patch of ca. 1 square meter was observed by JC in 2015 below the lake at Firebrook in Lexington (FAYE), where it might have been dispersed by the abundant geese that use this site, or perhaps planted. Another similar patch was recently discovered near Louisville (JEFF) in a wetland at Vissing Park, Floyd Co., Indiana (L. Darnell & P. Haragan, pers. comm.). The species shows signs of invasive behavior in southern Europe and East Asia, where it has been used in floating islands for purification of eutrophic water (Wang et al. 2013).