Eleocharis dulcis

Eleocharis dulcis, the water chestnut, or bi qi, 荸薺, is a species of aquatic sedge-grass that is found in marshes of the Old World tropics. Unlike Ling Jiao, which is an actual nut, the portion of the water chestnut eaten by humans is a fleshy, crunchy, tuber-like corm. Its crunchy texture explains its English name.

It is a perennial feature in Chinese cuisine, and is commonly available even in America both fresh and canned. It is generally eaten cooked, though, it has a sweeter taste raw. It is inadvisable to eat raw, though, unless thoroughly washed free of mud and peeled, as there may be nascent parasitic worm cysts on the surface of the corm. Cooked, sliced water chestnuts are often added to beef dishes to provide a complementary contrast of texture, as well as to detoxify the meat.

In Chinese Medicine, water chestnut clears heat from the lung and stomach, generates fluids, promotes digestion, and benefits the throat when it suffers from lung-heat or phlegm-heat syndromes. Water chestnut should not be eaten when the patient has deficiency cold syndromes or blood deficiency.