Eleocharis dulcis, the Chinese water chestnut or water chestnut, is a grass-like sedge native to Asia, tropical Africa, and Oceania. It is grown in many countries for its edible corms, but if eaten uncooked, the surface of the plants may transmit fasciolopsiasis.
The water caltrop, which also is referred to by the same name, is unrelated and often confused with the water chestnut.
Description
The water chestnut is not a nut but rather an aquatic vegetable that grows in marshes, under water, or in mud. It has stem-like, tubular green leaves that grow to about .
Distribution
The plant is native to Asia, tropical Africa, and Oceania.
Ecology
In the dry season of the Northern Territory in Australia, magpie geese eat the bulbs of water chestnuts, allowing them to put on fat for the wet season and ensuring they are ready for breeding. In the wet season, water chestnut leaves are used to build their floating nests.
Cultivation
The crop can be cultivated in paddies, wide by up to long to allow for mechanization, As it is an aquatic plant, it should always be submerged in approximately of water. The plant produces two types of subterranean rhizomes. Under long-daylength conditions, rhizomes grow horizontally and then turn upwards forming daughter plants. Under short-daylength conditions, the rhizomes grow downward and produce a corm at the tip. The photoperiod also significantly influences how fast the corms grow. Corms begin to develop much more slowly if the photoperiod exceeds 12 hours. The corms are also the propagating material. In China, yields are reported between ,
Pests
Chinese water chestnut is usually not very prone to pests;
Disease potential
If eaten uncooked, the surface of the plants may transmit fasciolopsiasis.
Uses
Nutrition
Raw water chestnuts are 74% water, 24% carbohydrates, 1% protein, and contain very little fat. In a 100-gram reference amount, raw water chestnuts supply of food energy, are rich (20% or more of the Daily Value, DV) in vitamin B<sub>6</sub> (25% DV), and contain moderate amounts of other B vitamins, manganese, and potassium (10% to 17% DV).
Culinary
thumb|[[Corm of Eleocharis dulcis]]
Raw water chestnuts are edible, and are slightly sweet and crunchy. The small, rounded corms have a crisp, white flesh and may be eaten raw, slightly boiled, or grilled, and often are pickled or tinned. Boiled water chestnuts have a firm and slightly crunchy texture, with a mild and slightly nutty flavor that may easily be overpowered by seasonings or sauces with which the water chestnut is served or cooked. They may be combined with bamboo shoots, coriander, ginger, sesame oil, and snow peas. Steamed or sauteed vegetable dishes may contain water chestnuts, such as noodle or rice recipes. They may also be added to minced-meat fillings and dishes, such as Cantonese dim sum-style steamed meatballs, to add a crunchy texture. The Thai dessert thapthim krop, with water chestnuts as its main ingredient, was named one of the world's best 50 desserts in 2019 by CNN Travel.
The corms are a popular ingredient in Chinese cuisine, in which they are most often eaten raw, sometimes sweetened. They also may be ground into a flour form used for making water chestnut cake, which is common as part of dim sum cuisine. They are unusual among vegetables for remaining crisp even after being cooked or canned, because their cell walls are cross-linked and strengthened by certain phenolic compounds, such as oligomers of ferulic acid. This property is shared by other vegetables that remain crisp in this manner, including the tiger nut, lotus root and spurge nettle root. The corms contain the antibiotic agent puchiin, which is stable to high temperature.
Other uses
Apart from the edible corms, the leaves can be used for cattlefeed, mulch or compost.