Be on the lookout for limnocharis. You must report all sightings within 24 hours.

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Native to Central America and South America (including Mexico, Bolivia, Paraguay and northern Argentina), limnocharis is an anchored aquatic plant with yellow flowers. Limnocharis colonises wetlands, restricting water flow and displacing native plants and animals.

Limnocharis is a serious agricultural and biodiversity threat to northern Australia, including the Northern Territory, northern Western Australia, and much of eastern Queensland. Infestations in northern Australia have been found in backyard ponds, ornamental lakes, farm drains and natural waterways.

You can identify limnocharis using:

You must manage the impacts of limnocharis on your land. You must not give away or sell limnocharis, or release it into the environment.

Scientific name

Limnocharis flava

Other names

  • yellow burr-head, yellow burrhead, yellow sawah lettuce, yellow sawah, sawah, sawah-flower rush, sawah flowering rush, yellow velvetleaf, velvetleaf, sawah lettuce, sawah flower rush, water cabbage
  • ตาลปัตรฤๅษี, talapat ruesi, นางกวัก, nang kwak, บอนจีน, bon chin, บัวค้วก, bua khuak, บัวลอย, bua loi, tarapat rusi, ผักก้านจอง, pak kan Jong, talapat ruesee, genjer, keo neo, emparuk, paku rawan, kaanz choong, 黄花蔺

Similar species


  • This anchored aquatic herbaceous plant has roots growing in mud/soil, not floating.
  • Plants grow up to 1m in height. They have erect stems and leaf blades.
  • Leaves are pale green and velvety. They grow up to 28cm long and 20cm wide, and have 11–15 parallel veins.
  • Leaf blade shape varies with age—narrow when young then more oval as the plant ages.
  • The triangular stem is a key identification feature (most aquatic plant stems are round). It can be up to 85cm long.
  • Yellow 3-petalled flowers are produced on stalks.
  • After flowering, spherical fruit (capsules) are produced on stalks. Each capsule is made up of 12–18 crescent-shaped segments called follicles.
  • Each follicle may contain up to 115 small brown seeds (up to 1,000 seeds per fruit).
  • Follicles and mature intact fruit capsules are buoyant.


  • Grows in saturated, fertile and muddy conditions
  • Grows as a perennial plant in areas with a lot of moisture


  • Visit Weeds Australia and click on the distribution tab to access the distribution map.

Life cycle

  • Can flower year-round
  • Reproduces by seed and vegetatively from plantlets
  • Can produce mature fruit in as little as 46 days
  • After producing capsules, flowering stalks bend towards the water and can produce vegetative plantlets. Once plantlets form roots in mud, they become independent plants

Affected animals

  • Native animals
  • Livestock



  • Colonises shallow wetlands and margins of deeper waterways
  • Displaces native plants and animals
  • Restricts water flow and traps silt


  • Restricts human and livestock access to water
  • Provides breeding areas for mosquitoes

How it is spread

  • Seeds are spread by running water, waterbirds and other animals.
  • Plantlets are spread in mud that sticks to vehicles, machinery and footwear.
  • Plants are spread by gardeners for ornamental or cultivation purposes.
  • Plants and seeds are spread through illegal importation/sales


Contact us online, by phone or in person if you find a plant you suspect may be limnocharis. We will provide advice on control.

Herbicide control

  • No herbicides are registered to specifically control limnocharis.

Biological control

  • There are no known biological control agents.

Legal requirements

  • Limnocharis is a category 2, 3, 4 and 5 restricted invasive plant under the Biosecurity Act 2014.
  • You must not keep, move, give away or sell limnocharis, or release it into the environment. Penalties may apply.
  • You must report all sightings within 24 hours.
  • You must take all reasonable and practical measures under your control to minimise the biosecurity risks associated with dealing with limnocharis. This is called your general biosecurity obligation (GBO).
  • Each local government must have a biosecurity plan that covers invasive plants and animals in its area. This plan may include actions to be taken on limnocharis. Some of these actions may be required under local laws. Contact your local council for more information.

Further information