Singoda flour, also known as water chestnut flour or water caltrop flour, is made from the ground starch of the singoda or water chestnut plant. The singoda plant (Trapa bispinosa) is an aquatic plant that produces an edible nut-like fruit. The origin of singoda flour can be traced to the Indian subcontinent, particularly in regions like India, Nepal, and Bangladesh, where the singoda plant is native. It has been used for centuries in traditional cuisines and is an essential ingredient in many regional dishes.