Trapa natans - Water Chestnut

Water Chestnut is an aquatic plant whose submerged stem reaches 12-15 ft in length, anchored into the mud by very fine roots. It has two types of leaves, finely divided, feather-like submerged leaves borne along the length of the stem, and undivided floating leaves borne in a rosette at the water's surface. The floating leaves have saw-tooth edges and are ovoid or triangular in shape, 2-3 cm long, on inflated leaf-stalks 5-9 cm long, which provide added buoyancy for the leafy portion. Four-petalled white flowers are borne for a long period. The fruit is a nut with four 1-cm, barbed spines. Seeds can remain viable up to 12 years, although most germinate within the first two years. The plant spreads by the rosettes and fruits detaching from the stem and floating to another area on currents or by fruits clinging to objects, and animals. Water Chestnut is found in Eurasia, Asia and Africa, from near sea level to 2700 m. It is also widely cultivated.