Khaki weed (Alternanthera pungens)

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Khaki weed grows in thick mats along the ground. It has spiny burrs that contaminate crops and injure people and animals

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How does this weed affect you?

Khaki weed is a hardy plant with spiny flowers and burrs. It:

can injure people and animals
is poisonous and can cause respiratory problems in some people
competes with native plants
outcompetes pastures, reducing productivity
contaminates crops including lucerne and hay
damages and devalues wool.

Human health

Khaki weed can cause hay fever, asthma and dermatitis in some people.

Livestock poisoning

Livestock usually avoid eating khaki weed. However, it:

is suspected of poisoning sheep and pigs
can cause skin problems, injuries around the mouth and feet and digestive problems in cattle
can cause staggers in horses that graze on areas containing large amounts of khaki weed.

What does it look like?

Khaki weed is a perennial creeping plant that forms dense mats over the ground. Stems die off in late summer or early winter and regrow from the roots in spring.

Leaves are:

up to 5 cm long
circular or oval shaped with a minute pointed tip
sparsely hairy along the underside of the midrib
on very short stalks
grow in opposite pairs and one leaf of each pair is larger than the other.

Flowers are:

yellow-green or green with 5 petals, two petals have sharp tips
surrounded by sharp pointed hairs
8-12 mm long and up to 10 mm wide
grouped together in clusters
grow in the leaf forks
present during spring and autumn.

Fruit are:

a prickly burr
about 1 cm long
straw coloured.

Seeds are:

yellowish or orange
round and 1-2 mm in diameter
shiny.

Stems are:

reddish
up to 60 cm long and grow from a central crown
covered with soft hairs.

Roots include:

a large, woody taproot, often black
smaller roots that grow from nodes along the stems.

Similar looking plants

Khaki weed looks similar to these other weeds:

Gomphrena weed (Gomphrena celosioides), which has larger, whitish flowers and no burrs.
Paraguay burr (Acanthospermum australe), which has burrs with hooks instead of spines.
Small matweed (Guilleminea densa) which does not have burrs.

It also looks similar to Native joyweeds (Alternanthera species), which do not have burrs.

Where is it found?

Khaki weed was first recorded in New South Wales in 1898 and is widespread. It grows in all regions of NSW and all Australian states.

It is native to South America.

What type of environment does it grow in?

Khaki weed grows in tropical, subtropical, semi-arid and warm temperate climates. Plants prefer light soil with high soil moisture in spring and summer.

Khaki weed has been found growing in:

stock routes and sale yards
native pastures with sandy soils
grasslands
orchards
disturbed areas such as roadsides
urban areas in gardens, lawns, parks and other recreation areas
caravan parks and camping grounds.

Maps and records

Recorded presence of Khaki weed 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

Khaki weed produces lots of seeds which can be viable for up to 5 years in the soil. The seeds are inside spiny burrs that are spread:

by attaching to fur and wool on livestock and wildlife
by shoes and clothing
on vehicles and machinery
in contaminated produce
in moving water.

By plant parts

Plants can grow from stem and root fragments. Fragments are spread by livestock, vehicles and machinery including cultivators and slashers.

References

Auld, B.A. & Medd, R.W. (1987). Weeds an Illustrated guide to the weeds of Australia. Inkata Press Sydney.

Hephner, A. J., Cooper, T., Beck, L. L., & Henry, G. M. (2013). Khakiweed (Alternanthera pungens Kunth) growth response to mowing height and frequency. HortScience, 48(10), 1317-1319.

Identic Pty Ltd. and Lucid (2016). Environmental Weeds of Australia Fact sheet: Alternanthera pungens Kunth Retrieved: 6 February 2026 from: https://keyserver.lucidcentral.org/weeds/data/media/Html/alternanthera_pungens.htm

Parsons, W.T., & Cuthbertson, E. G. (2001). Noxious weeds of Australia. 2nd edition. CSIRO publishing.

PlantNET (The NSW Plant Information Network System). Royal Botanic Gardens and Domain Trust, Sydney. Retrieved 6 February 2026 from: https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Alternanthera~pungens

Western Australian Herbarium (1998–). Florabase—the Western Australian flora. Department of Biodiversity, Conservation and Attractions. Retrieved 6 February 2026 from: https://florabase.dbca.wa.gov.au/browse/profile/2653

More information

Control

If possible, control khaki weed at the beginning of the growing season before plants produce seed. Combining control techniques may give the best results. Monitor sites regularly.

Prevention

To prevent the spread of Khaki weed:

check shoes and clothing and remove burrs
avoid driving through infested areas if possible
clean vehicles and equipment that have been in invested areas
purchase fodder free of khaki weed
grow dense competitive turf and mow regularly.

Physical removal

Small, isolated plants and infestations can be hand pulled or dug out. Make sure all the tap root is removed and disposed of appropriately to stop the plant from re-growing.

Disposal

Contact your local council for advice about disposing khaki weed.

Cultivation

Cultivation can kill seedlings and established plants. Though deep cultivation is needed to prevent regrowth of taproots. Cultivation should be repeated to kill any plants that might have regrown from root or stem fragments spread during previous cultivation. Equipment should be cleaned thoroughly to prevent the spread of this weed.

Chemical control

Spraying

Spray actively growing plants. Check the herbicide labels for the best time of year to apply herbicides and ensure all of the foliage is covered.

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 12362 Expires 28/02/2028
Triclopyr 300 g/L + Picloram 100 g/L (Various products)
Rate: 2.0 L/ha
Comments: Only for use in in tropical grass pastures. Spray when weeds are small and actively growing, preferably before flowering and when secondary roots are present on the sown pasture. See permit for further critical comments.
Withholding period: Nil.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

2,4-D 300 g/L + Picloram 75 g/L (Tordon® 75-D)
Rate: 650 mL in 100 L of water
Comments: Spray during full leaf in summer.
Withholding period: Do not graze or cut crops (except sugar cane 8 weeks) or pastures for stock food for 7 days after application.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

2,4-D amine 625 g/L (Various products)
Rate: 1.1 – 2.2 L/ha
Comments: Spray in pastures, seedlings only.
Withholding period: 7 days withholding for grazing
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

Amitrole 250 g/L + Ammonium thiocyanate 220 g/L (Various products)
Rate: 1.1 L in 100 L of water
Comments: Spot spray when weeds are actively growing, immediately prior to flowering. Respraying will be necessary to destroy regrowth and seedlings. For non-crop areas around buildings commercial and industrial areas, domestic and public service areas, right-of ways.
Withholding period: Nil
Herbicide group: 34 (previously group Q), Inhibition of lycopene cyclase
Resistance risk: Moderate

MCPA 340 g/L + Dicamba 80 g/L (Kamba® M)
Rate: 4-7 L per ha
Comments: Boom spray for grass pastures. When necessary, a second treatment may be made after 4 weeks.
Withholding period: Do not graze or cut for stock food for 7 days after application.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

MCPA 340 g/L + Dicamba 80 g/L (Kamba® M)
Rate: 100 mL per 15 L
Comments: Knapsack spray for grass pastures. When necessary, a second treatment may be made after 4 weeks.
Withholding period: Do not graze or cut for stock food for 7 days after application.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

MCPA 340 g/L + Dicamba 80 g/L (Kamba® M)
Rate: 400 mL/100 L of water
Comments: Spray in grass pastures. When necessary, a second treatment may be made after 4 weeks.
Withholding period: Do not graze or cut for stock food for 7 days after application.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
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.
Murray	Regional Recommended Measure* (for Regional Priority - Asset Protection) Land managers should reduce the impact of the plant on assets of high economic, environmental and/or social value.
	*To see the Regional Strategic Weeds Management Plans containing demonstrated outcomes that fulfil the general biosecurity duty for this weed click here

For technical advice and assistance with identification please contact your local council weeds officer.

Reviewed 2026