Monochoria vaginalis (N.L. Burman) Kunth

Monochoria vaginalis (N.L. Burman) Kunth




Ponte­deria vaginalis N.L. Burman, P. pauciflo­ra Blume, Gomphima vaginalis (N.L. Bur­man) Rafinesque.

Vernacular Names


Kelayar, keladi agak.


Oval-leaved pondweed, oval-leaved monochoria, pickerel weed.


Eceng padi, eceng leutik, wewehan.


Biga-bigaan (Tagalog), gabing uwak (Tagalog), bilagut (Ilocano).




Khakhiat, ninlabon (Central), phakhin (North-eastern).


Rau ch[os]c, rau m[as]c l[as] thon.

Geographical Distributions

Monochoria vaginalis is native to South Asia, throughout Southeast Asia, ex­tending also to China, Japan, Fiji islands and northern Australia. It has become naturalised in Hawaii, California and in rice fields of Russia and Italy. It is sometimes cultivated as a vegetable.


Monochoria vaginalis is an annual herb and rarely rhizomatous. The stems are creeping or ascending. The petiole is up to 50 cm long. The leaf blade is linear or lance-shaped to ovate and measuring 2-21 cm x 0.2-10 cm. The inflorescence is very variable, with (1-)2-7(-20) flowers that become strongly deflexed in fruit. The peduncle is 2-50 cm long. The lower spathe is with sheath 1-3.7 cm long. The petiole is 0.5-7 cm, with linear or lance-shaped to ovate or cordate blade and measuring 1.3-10 cm x 0.3-15 cm. The upper spathe is 1-3.5 cm long. The pedicel is up to 3 cm long. The tepals measure 8-15 mm x 8 mm. There are 6 stamens where 5 of them are yellow and 1 blue. The style is 2-5 mm long. The fruit is ellipsoidal to ovoid and measuring 0.8-1.2 mm x 0.4-0.7 mm. The seed is ovoid, measuring 0.5-1 mm x 0.3-6 mm and with 8-10 narrow wings. (1)

Ecology / Cultivation

Monochoria vaginalis occurs from the plains up to 1500 m. It is most common in eutrophic water, but may be found also in brackish and oligotrophic water. It is a stress-tolerant ruderal.

Line Drawing / Photograph




  1. Footnote not available