Latin name

Sphenoclea zeylanica Gaertner

Family

Sphenocleaceae

Common name(s)

Gooseweed

Synonym(s)

Gaertnera pongati Retz., Pongatium indicum Lam., P. zeylanicum (Gaertner) Kuntze, P. spongiosum Blanco, Rapinia herbacea Lour., Reichelia palustris Blanco

Geographical distribution

South and Southeast Asia: Bangladesh, Cambodia, India, Indonesia, Lao PDR, Malaysia Myanmar, Nepal, Pakistan, Philippines, Sri Lanka, Thailand, and Vietnam.

Rest of the world: Bolivia, Colombia, Costa Rica, Ecuador, Iran, Madagascar, Nicaragua, Nigeria, Paraguay, Peru, Senegal, Solomon Islands, Surinam, Tanzania, United States, Venezuela, and Zambia.

Morphology

An erect, branched herb, 7—150—cm—tall.

Stem: smooth and fleshy, hollow, much branched and with white, spongy (aerenchymatous) tissues at base.

Leaf: simple and spirally arranged light green; blades oblong to lance-shaped, narrowed at the tip, 10—cm—long, borne on short stalks.

Inflorescence: green, cylindrical, 7.5—cm—long and dense terminal spike; flowers densely crowded, white to greenish, sessile.

Close-up of inflorescence (IRRI).

Fruit: a flat, 4—5—mm—diameter globular capsule.

Seed: yellowish brown, 0.5—mm—long.

Biology and ecology

Herbaceous annual weed, reproducing by seeds; seeds usually dormant and germination is initiated by light. Flowers throughout the year and sets fruit.

Found in wet ground and prefers stagnant water; widespread.

Agricultural importance

Reported to cause yield loss of 25—50% in rice. Young plants and tips of older plants are steamed and eaten as a vegetable in Indonesia.

Management

Cultural control: closed crop canopy limits germination and growth of the weed.

Chemical control: Anilofos, bensulfuron, cinosulfuron, chlorimuron, metsulfuron, prazosulfuron, thiobencarb, oxadiazon, piperophos, and propanil are reported to be effective.

Selected references

Airy Shaw HK. 948. Sphenocleaceae. Flora Malesiana Ser. 1 Vol 4:27-28.

Holm LG, Plucknett DL, Pancho JV, Herberger JP. 1977. The world's worst weeds: distribution and biology. Honolulu, Hawaii (USA): The University Press of Hawaii. 609 p.

Kenji Noda, Teerawatsakul M, Prakongvongs C, Chaiwiratnukul L. 1985. Major weeds in Thailand. Bangkok (Thailand): Department of Agriculture. National Weed Science Research Institute Project. 142 p.

Merrill ED. 1976. A flora of Manila. Manila (Philippines): Department of the Interior, Bureau of Science. 491 p.

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

Moody K, Munroe CE, Lubigan RT, Paller Jr. EC. 1984. Major weeds of the Philippines. College, Laguna (Philippines): Weed Science Society of the Philippines, University of the Philippines at Los Baños. 328 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