Edible spike rush, Chinese water-chestnut
Eleocharis dulcis

Family: Cyperaceae

What it is like

A herb which grows in water. It is a tufted sedge with round green stems. The bases are covered with brown sheaths. The stem is about a metre high and 1 cm across. It grows 30-200 cm high. From the top of each planted corm, several slender horizontal rhizomes radiate out into the mud, each terminating in a corm. The edible part consists of a flattened corm. The rhizome is short. Under the ground there are stolons bearing tubers. The tubers are almost round and have 4-6 distinct rings. They are about 1 cm across but can be 4 cm across. They are dark brown. The stems are tufted and slender. There are fine lines along the stems. The leaves are reduced to thin tube like sheaths. These are purplish. Each plant produces these long tubular leaves that project above the water surface. The flower spike is on the end of the plant. There are many flowers. The flowers are 1.5-6 cm long by 3-6 mm wide. The fruit is a nut 1.5-2 mm long.

There are about 160-200 Eleocharis species. There are 60 species in tropical America.

Where it is found

A tropical plant. It suits tropical and subtropical locations. It suits humid monsoonal conditions. It is found in the Philippines in open wet places and shallow water throughout the islands. It grows in fresh water swampy grounds or in shallow water. It grows in wetlands. It is also found in rice fields. It needs at least 220 frost free days. It needs a soil temperature above 14-15.5°C for germination of the corms. It needs a pH of 6.9-7.3. It can be grown up to 1,200 m altitude. It suits plant hardiness zones 9-12.

Countries/locations it is found in

Africa, American Samoa, Asia, Australia, Botswana, Burkina Faso, Cambodia, China, East Africa, East Timor, Fiji, FSM, Gambia, Ghana, Guam, Guinea, Guinée, Guinea-Bissau, Hawaii, India, Indochina, Indonesia, Japan, Japan-Ryukyu Islands, Korea, Laos, Liberia, Madagascar, Malaysia, Mali, Micronesia, Mozambique, Myanmar, New Caledonia, Nigeria, North America, Northeastern India, Pacific, Pakistan, Papua New Guinea, Philippines, Pohnpei, Samoa, SE Asia, Senegal, Sierra Leone, Singapore, South Africa - Natal, Southern Africa, Sri Lanka, Taiwan, Tasmania, Thailand, Timor-Leste, Tonga, Torres Strait, USA, Vietnam, West Africa

How it is used for food

The tubers are cooked and eaten. The corms can be eaten raw, roasted or boiled after they have been peeled. Normally, they are cut into small slices and added to soup or to fish and meat dishes. They can be sweetened for desserts.

It is a commercially cultivated vegetable. The corms are canned and exported. They are sold in local markets.

Edible parts

Tubers, corms, vegetable, roots

How it is grown

Plants can be grown by division or tubers. They are put in holes 20-30 cm deep. Fields are flooded after planting then allowed to drain. When top growth is 20-30 cm high fields are flooded to at least 10-12.5 cm. A spacing of 75 cm x 75 cm is suitable. 500 kg of corms per hectare are required for planting.

Corms mature after 7-8 months. Yields of 20-40 t per ha are possible.

Its other names

Local names

Ankurladj, Apulid, Biqi, Buslig, Chee-Chang, Chikai, Chinese Water Chestnut, Go nung, Ground-chestnut, Haeo cheen, Haeo-song krathiem, Inu kuro guwai, Kakthum, Kirlinja, Kokthum, Kurogu-wai, Kuwai, Li zi, M'pofa, Ma Ti, Ma-Tai, Macre, Mampufa, Mardhar, Mem plong khtim, Okuroguwai, Pani phul, Po-chi, Singhara, Tall spike-rush, Tike, Uchaga-lane, 'Utu'utu, Waterchestnut, Waternut, Wetmye-u, Ye thit eir thee

Synonyms

Andropogon dulce Burm. f.; Bolboschoenus maritimus subsp. tuberosus (Desf.) J. Sojak; Eleocharis austrocaledonica Vieill.; Eleocharis dulcis var. tuberosa (Schult.) T. Koyama; Eleocharis equisetina J. Presl. & C. Presl; Eleocharis esculenta Vieill. Eleocharis indica (Lour.) Druce; Eleocharis plantaginea R.Br.; Eleocharis plantaginoidea W.F.Wight [Illegitimate]; Eleocharis sphacelata Boeck.; Eleocharis tuberosus Roem & Schult.; Eleocharis tumida (Roxb.) Schult.; Limnochloa plantaginea (Retz.) Nees; Limnochloa tumida (Roxb.) Nees; Scirpus dubius Roxb.; Scirpus plantagineus Retz.; Scirpus plataginoides Rottb.; Scirpus tuberosus Roxb. [Illegitimate]; Scirpus tumidus Roxb.;