Why Is A Water Chest Nut Called A Water Chest Nut?

The water chestnut, also known as the water caltrop can refer to any of two species of the plant genus Trapa. That is, T. natans as well as T. bicornis. The fact that both these species of Trapa are floating, aquatic, annual plants combined with their resemblance to chestnuts in shape as well as colouring probably gave rise to the name 'water chestnut'.

These plants give ornately shaped fruits which bear a resemblance to a bull's head, each holding a single especially big starchy seed. In China, the water chestnut has been cultivated for these seeds for no less than 3,000 years.

There is also the Chinese water chestnut (that is, Eleocharis dulcis), which is more often simply referred to as the water chestnut. However it should not be confused with the water caltrop, which although is also called a water chestnut, is unrelated.