Trapa natans , introduced to New York State in the late 1800s, now infests sites throughout the northeastern United States. The plant has aggressive growth habits and forms extensive surface mats, restricting both recreational and commercial uses of infested water bodies. It is reported that seeds may remain viable for up to twelve years, making eradication of the plant especially difficult. Research continues on control methods for this species. The Chinese water chestnut, Eleocharis dulcis , is grown legally and successfully in Florida as a food crop.
Confusion is frequent since both plants share the same common name of water chestnut.