Bullnut

Trapa natans L. is a species in the Lythraceae family, native to a wide range including parts of North America, Europe, and Asia. It is commonly known as bullnut or water caltrop and is cultivated for its edible nuts. The species has been subject to taxonomic discussion regarding its type material, with a neotype designated by Verdcourt in 1986 due to the lack of suitable original material. The plant is also referred to by other names such as buffalo nut, bat nut, and water nut, though 'water chestnut' is more commonly used for Eleocharis dulcis.