Water Caltrop

The water caltrop, water chestnut, buffalo nut, bat nut, devil pod or Singhara (¿¿¿¿¿¿¿) or Pani-fol (¿¿¿¿¿¿) is either of two species of the genus Trapa: Trapa natans and Trapa bicornis. Both species are floating annual aquatic plants, growing in slow-moving water up to 5 meters deep, native to warm temperate parts of Eurasia and Africa. They bear ornately shaped fruits, which in the case of T. bicornis resemble the head of a bull, each fruit containing a single very large starchy seed. It has been cultivated in China and India for at least 3,000 years for the seeds.