Yellow burrhead (Limnocharis flava)

WEED ALERT: STATE PROHIBITED WEED
If you see this plant contact your council weeds officer, the NSW Invasive Plants & Animals Enquiry Line 1800 680 244 or email weeds@dpi.nsw.gov.au
Also known as: limnocharis

Profile

Impact

Yellow burrhead is a perennial aquatic plant that has the potential to become a major weed of freshwater systems in tropical and subtropical Australia.

It can alter the natural flow of water in channels and drains, causing silt to build up and eventually block water flow.

Unusual foliage and attractive yellow flowers make yellow burrhead an appealing pond plant, and it may have entered the country as a garden ornamental.

Yellow burrhead has the potential to invade and establish in lakes, rivers, dams and wetlands across northern Western Australia, the Northern Territory, coastal Queensland and northern New South Wales (NSW).

Distribution

Yellow burrhead is native to Central America, from Mexico through to Paraguay, northern Argentina and the Caribbean.

It has naturalised in the USA, South America, India and south-east Asia. It is a major weed in Malaysia, Sri Lanka and Indonesia where it threatens wetlands and has become problematic in rice fields and irrigation channels. Severe infestations have forced farmers to abandon rice paddies.

In 2001 several small populations were discovered in garden ponds in northern Queensland. All known infestations of yellow burrhead are currently under eradication programs, with infestations still occurring in the Queensland districts of Cairns and Townsville.

There are currently no known infestations of yellow burrhead in NSW and it is banned from entry into Australia.

Distribution map

Spread

Yellow burrhead reproduces vegetatively and by seed. Large numbers of small seeds are produced every year. Mature fruit can be produced in as little as 42 days, and then released onto the water surface. The buoyant seeds are released from the fruit and can float to new locations in moving water. Seeds may also be spread by contaminated mud attached to vehicles, footwear, animals and water birds.

New plantlets also develop after a flowering stem loses all its flowers and bends over into the mud. The end of the stem takes root in the mud and develops a new plant or can break off and float away to form a new infestation.

Description

Yellow burrhead is an erect, anchored, perennial plant. It prefers fertile, shallow, still water and can grow up to 1 m above the water surface. In year-round wet conditions it behaves as a perennial and as an annual in areas that are seasonally dry.

Key identification features

  • Leaf stems grow in clumps from seed or daughter plants. They are green, triangular and fleshy, and grow to 75 cm in height.
  • Leaves are green, with 11–15 parallel veins. Leaf shape varies with age. Leaves are 5–30 cm long and 4–25 cm wide. Young leaves are narrow, broadening and becoming more oval-shaped with age.
  • Flowers are three-petalled, small, pale yellow and cup-shaped, growing in clusters of 5–15. Plants flower year-round.
  • Fruit is round, up to 2 cm wide and made up of 12–18 crescent-shaped segments. Each fruit can produce around 1000 seeds.
  • Seeds are about 1.5 mm long, dark brown and horseshoe-shaped, with obvious ridges.

Habitat

Yellow burrhead thrives in nutrient-enriched water and can quickly colonise shallow wetlands and the edges of deeper waterways, where it can outcompete and dominate other aquatic plants.

Acknowledgements

2006 edition prepared by Annie Johnson and Rachele Osmond; 2013 edition reviewed by Rod Ensbey; edited by Elissa van Oosterhout.

References

Hosking JR, Sainty GR, Jacobs SWL & Dellow LL (in prep) The Australian WeedBOOK

Limnocharis (Limnocharis flava) Fact sheet (2011) Queensland Department of Employment, Economic Development and Innovation.

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Control

If you suspect you have found yellow burrhead, immediately contact a local council weeds officer who will assist with identification, removal and eradication.

Herbicide options

WARNING - ALWAYS READ THE LABEL
Users of agricultural or veterinary chemical products must always read the label and any permit, before using the product, and strictly comply with the directions on the label and the conditions of any permit. Users are not absolved from compliance with the directions on the label or the conditions of the permit by reason of any statement made or not made in this information. To view permits or product labels go to the Australian Pesticides and Veterinary Medicines Authority website www.apvma.gov.au

See Using herbicides for more information.


PERMIT 9907 Expires 31/03/2020
Glyphosate 360 g/L (Only products registered for aquatic use)
Rate: Up to 200 ml in 10 L of water
Comments: Spot spray application
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate


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Legal requirements

The content provided here is for information purposes only and is taken from the Noxious Weeds (Weed Control) Order 2014 published in the NSW Government Gazette, detailing weeds declared noxious in New South Wales, Australia, under the Noxious Weeds Act 1993. The Order lists the weed names, the control class and the control requirements for each species declared in a Local Control Authority area.

Area Class Legal requirements
All of NSW 1 State Prohibited Weed
The plant must be eradicated from the land and that land must be kept free of the plant

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Reviewed 2014