Echinochloa colonum

Scientific Name Echinochloa colonum (L.) Link, Panicum colonum L.
Synonyms Brachiaria longifolia Gilli, Echinochloa colona, Echinochloa verticillata Berbaut, Milium colonum (L.) Moench, Panicum colonum Linneaus
Common Names English: Awnless barnyard grass (Australia), jungle rice (United States), Swampgrass; German: Dekkangras, Schamahirse; French: Panic des cultures; Spanish: Cola de caballo; Portuguese: Capim-arroz
Description Annual, widespread, tuft-forming, seed-propagated grass weed of warmer regions with fibrous, rather shallow roots, up to 60 mm (2.36 inch).


Characteristic Features

Very short, reduced glume and dense form of the panicle.


Culms stout, erect to decumbent, often branching from the base, rather tall (30-60 cm) (11.81 - 23.62 inch).


Leaf blades glabrous, elongate, 3-6 mm (0.118 - 0.24 inch) wide, 10-15 cm (3.93 - 5.9 inch) long, light green with a white midrib. The first leaves are grayish dull-green, often with several widely spaced purple bands on the leaf blade surface. Youngest leaf is rolled.
Ligule absent.
No auricles.
Sheath glabrous.

Propagation Organs


Panicle erect or nodding, green or purple-tinged, 5-15 cm (1.96 - 5.9 inch) long. (3-)8-10 racemes, 1-2 cm (0.39 - 0.78 inch) long, ascending. Spikelets crowded, about (1-)2-3 mm (0.039 - 0.118 inch) long.
First glume nearly half as long as the spikelet; second glume and sterile lemma with short bristly hairs on the nerves, awnless.

Flowering Period

Summer - autumn.


Caryopsis 1.7-2 mm (0.067 - 0.078 inch) long, whitish.


Germination in spring and summer.

Viability of Seeds

Very persistent in soil seed bank.


By seeds, produced in great quantities (40,000 seeds per plant).



Cultivated areas, waste grounds, ditches and fields.


Fairly wide range of soils, but E. colonum is most common in loam, silt and clay soils in low places.

Agricultural Importance

Echinochloa colonum is a cosmopolitan weed in subtropical and tropical areas. It can be an important weed in rice. Mature plants of E. colonum resemble the rice plant but can grow taller and thus compete better for sunlight. They mature easily, producing about 42,000 seeds per plant. Yield loss from this weed can reach 43%, especially in direct seeded rice.
The weed is a host of diseases such as tungro and rice yellow dwarf.


Useful non-chemical contribution to Integrated Weed Management

Hand weeding or use of a hoe during the early growth stages of the weed.

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