Common Name: Chinese Water Chestnut

General Information

Eleocharis dulcis is a tufted, perennial rush-like plant with stems 50 - 200cm tall. The plant has short rhizomes and elongated stolons, most of these terminated by a globose tuber.
The plant is harvested from the wild for local use as a food, medicine and source of materials. It is widely cultivated for its edible tubers in China, there are some named varieties[, ].

Known Hazards

None known

Botanical References

Range

Tropical and subtropical areas of Africa; eastern Asia from Pakistan and China eastwards to thePhilippines, New Guinea, Australia, western Pacific

Habitat

Marshy land and shallow water[]. The edges of seasonal swamps in Australia[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	1.00 m
Cultivation Status	Cultivated, Wild

Cultivation Details

Eleocharis dulcis grows well in tropical and sub-tropical areas below an elevation of 1,200 metres[]. Plants perform best at temperatures between 30 - 35°c during the leafy stage of growth, and about 5°c lower when the tubers are being formed[]. A minimum soil/water temperature of 15°c is required for adequate development of the corms[].
A plant of marshes and shallow water, it prefers slightly acid soil conditions and a sunny position[]. Requires a rich fertile soil[]. Grows best in rich clay soils[]. Prefers a pH in the range 6.9 - 7.3[]. Some forms can grow in brackish water[]. Growing plants should be grown in a water depth of at least 10cm until about 20 - 30 days prior to harvesting when the land can be allowed to drain naturally[].
The plant requires a 7 - 8 month frost-free growing season in order to produce a crop[, , ].
Yields of 20 - 40 tonnes per hectare can be achieved[].
The tubers should be harvested at the end of the growing season and stored in a cool damp but frost-free position until replanting[].

Edible Uses

Corm - raw or cooked[, , , , ]. A delicious taste, it is sweet and crisp when fully ripe and is starchy before that[, ]. A sweet nutty flavour[]. Widely used in Chinese cooking, especially in chop suey. A flour or starch can be made from the dried and ground up corm and this is used to thicken sauces and to give a crisp coating to various deep-fried foods[]. The root is about 4cm in diameter[], it contains about 36% starch[]. A nutritional analysis is available[].

The plant is used for making salt in Zimbabwe[]. No more details.

Medicinal

The plant is used to treat a number of ailments including abdominal pain, amenorrhoea, hernia and liver problems[].

The expressed juice of the tuber is bactericidal[].

Other Uses

The leaf stems are used for weaving bags, mats, baskets, hats etc[, , ].

Propagation

Seed - we have no details for this species but suggest sowing the seed as soon as it is ripe in a greenhouse. Only just cover the seed and place the pot in 3cm of water to keep the soil wet. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts.
Division. Harvest the tubers at the end of the growing season, store them in a cool but frost-free place over the winter and plant them out in early spring.