Yellow burrhead (Limnocharis flava)
Yellow burrhead is a water weed with yellow cup-shaped flowers. It can block water channels and outcompete native plants.
Profile
How does this weed affect you?
Yellow burrhead is an aquatic weed that:
- outcompetes native aquatic plants
- reduces food and habitat for fish and other aquatic animals
- causes silt to build up which can reduce the width of waterways
- can slow or block water flow in natural waterways, agricultural channels and drains
- restricts access to the water for people and animals
- creates habitat for mosquitos.
What does it look like?
Yellow burrhead is an erect plant anchored in mud or sediment. It can grow up to 1 m above the water surface. In year-round wet conditions, it behaves as a perennial. In seasonally dry areas it grows as an annual.
Leaves are:
- pale green
- 5–30 cm long and 4–25 cm wide
- velvety with 11–15 parallel veins
- narrow when young
- broader and more oval-shaped as they age
- on triangular, fleshy stalks up to 85 cm long that produce milky sap when broken.
Flowers are:
- pale yellow with three petals
- cup-shaped
- 2-4 cm wide
- in clusters of 2–15
- present year-round.
Fruit are
- round capsules
- green, turning brown as they mature
- up to 2 cm wide
- made up of 12–18 crescent-shaped segments (each containing up to 115 seeds), which separate when ripe.
Seeds are:
- dark brown to black
- 1–1.5 mm long
- horseshoe-shaped with obvious ridges.
Stems are:
- triangular in cross section
- up to 85 cm long
- contain a milky sap.
Where is it found?
There are no known infestations of yellow burrhead in NSW but it has the potential to invade northern NSW. Eradication programs are in place for infestations in northern Queensland.
Yellow burrhead is native to Central America. 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 invades wetlands, rice fields and irrigation channels.
Yellow burrhead grows in shallow water in streams, freshwater swamps, wetlands, ditches and along riverbanks. It can also grow next to, rather than in water in humid environments.
Maps and records
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Recorded presence of Yellow burrhead during property inspections (Map: Biosecurity Information System - Weeds, 2017-2026)
These records are made by authorised officers during property inspections under the Biosecurity Act 2015. Officers record the presence of priority weeds in their council area and provide this to the NSW Department of Primary Industries. Records reflect the presence of the weed on the date of inspection.
How does it spread?
By seed
Yellow burrhead can produce flowers in as little as 23 days after seedlings emerge and plants can produce mature fruit in as little as 46 days. Capsules contain, on average, 1000 seeds and may contain up to 1500 seeds. Seeds can remain viable for at least 4 years. Each plant can produce up to a million seeds per year.
Most seeds are spread by water. Mature fruit falls off the plant and floats downstream and the seeds sink when released from the fruit. Seeds can also be spread in contaminated mud stuck to vehicles, machinery, footwear and animals, especially water birds.
By plant parts
New plantlets grow after the 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 it can break off and float away to form a new infestation.
References
Abhilash, P. C., Singh, N., Sylas, V. P., Kumar, B. A., Mathew, J. C., Satheesh, R., & Thomas, A. P. (2008). Eco-distribution mapping of invasive weed Limnocharis flava (L.) Buchenau using geographical information system: implications for containment and integrated weed management for ecosystem conservation. Taiwania, 53(1), 30-41.
Brooks, S. J., Panetta, F. D., & Galway, K. E. (2008). Progress towards the eradication of mikania vine (Mikania micrantha) and limnocharis (Limnocharis flava)in northern Australia. Invasive Plant Science and Management, 1(3), 296-303.
Brooks, S. J., Weber, J. M., Setter, S. D., & Akacich, B. A. (2008). Seed production and maturation of Limnocharis flava (L.) Buchenau in the field and glasshouse. In Proceedings from the Sixteenth Australian Weeds Conference.
Nayar, B. K., & Sworupanandan, K. (1978). Morphology of the fruit and mechanism of seed dispersal of the freshwater weed Limnocharis flava. In Proceedings of the Indian Academy of Sciences-Section B (Vol. 87, No. 2, pp. 49-53). Springer India.
Queensland Government. (2025). Restricted invasive plant: Limnocharis flava. Retrieved 17 March 2025 from: https://www.publications.qld.gov.au/ckan-publications-attachments-prod/resources/97410277-a819-4d3e-990c-fa007a7ebbe9/limnocharis.pdf?ETag=9cd96b3ab58a9a3a1af2feeb9df2b974
Weber, J. M., & Brooks, S. J. (2013). The biology of Australian weeds 62.'Limnocharis flava'(L.) Buchenau. Plant Protection Quarterly, 28(4), 101-113.
More information
Control
Please do not attempt to treat or dispose of this weed yourself. Report this plant if you see it anywhere in NSW by calling the helpline listed at the top of this page immediately.
NSW DPIRD, Agriculture and Biosecurity will lead an initial response for the treatment and disposal of the plant to stop it from spreading.
Herbicide options
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 31/03/2030
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: 9 (previously group M), Inhibition of 5-enolpyruvyl shikimate-3 phosphate synthase (EPSP inhibition)
Resistance risk: Moderate
Biosecurity duty
The content provided here is for information purposes only and is taken from the NSW Biosecurity Act 2015 and its subordinate legislation, and the Regional Strategic Weed Management Plans (published by each Local Land Services region in NSW). It describes the state and regional priorities for weeds in New South Wales, Australia.
| Area | Duty |
|---|---|
| All of NSW | General Biosecurity Duty All pest plants are regulated with a general biosecurity duty to prevent, eliminate or minimise any biosecurity risk they may pose. Any person who deals with any plant, who knows (or ought to know) of any biosecurity risk, has a duty to ensure the risk is prevented, eliminated or minimised, so far as is reasonably practicable. |
| All of NSW |
Prohibited Matter
A person who deals with prohibited matter or a carrier of prohibited matter is guilty of an offence. A person who becomes aware of or suspects the presence of prohibited matter must immediately notify the Department of Primary Industries |
Reviewed 2026
