Latin name

Eleocharis dulcis Trinius ex Hensch.

Family

Cyperaceae

Common name(s)

Chinese water chestnut, waternut, and ground chestnut

Synonym(s)

Eleocharis plantaginea R.Br. and E. tuberosa Schult., Scirpus plantagineus (Fl. Hongk. Suppl.) Retz., S. tuberosus Roxb.

Morphology

Perennial, variable, up to 200—cm—tall; short rhizomes and elongated stolons bearing brown to black tubers 1—4—cm across.

Stem: tufted, terete, slender, and with fine longitudinal lines, smooth and greenish to dark green, and divided into partitions (septate) in transverse manner.

Leaf: reduced to a purplish, membranous sheath, oblique at the apex and 5—20—cm—long.

Inflorescence: single, terminal, cylindrical; straw-colored and gradually narrowed toward the apex; spikelet 15—50—mm—long and 3—4—mm—wide.

Fruit: glossy brown, biconvex nut about 2—mm—long.

Biology and ecology

Propagates by stolon, tubers, and seeds.

Tuber gives rise to an apical bud, aerial shoots, and roots or rhizomes, which later form a basal bulb or corm; rhizomes may also form an extensive network underground.

A single tuber produces 200 plants in a year; most tubers are located 15—cm below the soil.

Prefers aquatic environments; commonly found in rice fields, swamps, and wastelands.

Agricultural importance

Competes strongly with rice and grows well in acid sulfate soils.

Tubers (improved form-Chinese water chestnut, emping teki) served as food in sliced, boiled, canned, or pickled form. Stems used for making mats.

Management

Cultural control: exposing tubers to desiccation by plowing 20—cm deep can limit populations.

Chemical control: Glyphosate application to growing undisturbed plants can be effective.

Selected references

Holm L, Doll J, Holm E, Herberger J. 1997. World weeds: natural histories and distribution. John Wiley & Sons, Inc. USA. 1,129 p.

Kern JH. 1974. Cyperaceae. Flora Malesiana Ser. 1 7(3): 435-753.

Moody K. 1989. Weeds reported in rice in South and Southeast Asia. Manila (Philippines): International Rice Research Institute. 442 p.

Pancho JV, Obien SR. 1995. Manual of ricefield weeds in the Philippines. Muñoz, Nueva Ecija (Philippines): Philippine Rice Research Institute. 543 p.

Soerjani M, Kostermans AJGH, Tjitrosoepomo G. 1987. Weeds of rice in Indonesia. Jakarta (Indonesia): Balai Pustaka 716 p.

Contributors

JLA Catindig, RT Lubigan, and DE Johnson