Macquarie Valley Weeds Committee & Lachlan Valley Weeds Advisory Committee


Bathurst Burr

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Botanical Name: Xanthium spinosum
Other Common Names:


Class Regions
Class 4Bland Shire Council,Bogan Shire Council,Bourke Shire Council,Brewarrina Shire Council,Cabonne Council,Castlereagh Macquarie County Council,Cobar Shire Council,Cootamundra Shire Council,Cowra Council,Forbes Shire Council,Lachlan Shire Council,Mid-Western Regional Council,Narromine Shire Council,Orange City Council,Parkes Shire Council,Upper Macquarie County Council,Weddin Shire Council,Wellington
Landholder Responsibilities: The growth and spread of the plant must be controlled according to the measures specified in a management plan published by the local control authority.
Why Is It Bad?: Bathurst Burr is a significant pasture weed affecting the overall quality of agricultural produce through pasture competition and fleece contamination. Burrs cannot be removed mechanically from contaminated clips and the wool has to be carbonised with acid, which imposes a high additional cost on wool production.


Habit: Herb
Leaves: Leaves are shiny dark green on top and whitish-green on the reverse side. They grow up to 7 cm long. Most form into 3 lobes (divisions); the centre lobe is usually about 4 cm long and much longer than the other two. The leaves have prominent midveins.
Flowers: Flowers are creamy-green, small and inconspicuous, making them difficult to see. They grow in summer and autumn. Male flowers grow at the end of the stems; female flowers grow lower down, in the leaf axils.
Fruit: Straw coloured ; a somewhat ellipsoid burr the body of which is 1 to 1.5 cm long and 4 to 5 mm wide, sessile, usually solitary; armed with numerous slender yellow hooked spines and sometimes 1 or 2 straight terminal spines.
Roots: Branched taproots that support the plants

Control Methods

Manual Removal: Bathurst Burr can be chipped out manually but care needs to be taken as developing burrs can continue to mature on cut plants. Plants should be destroyed afterwards to ensure seeds do not continue to spread.
Chemical Use: Herbicides are often the prefered method of control with many options available. Spraying is most effective on actively growing seedlings, but can be used in various situations successfully. It is best to apply chemicals before seed set to help prevent burrs forming.
Slashing & Cutting: Can be used as a useful control method but must be done before burrs form.
Biological Control: Research into use of biological control agents sourced from South America is still underway. Some other agents such as the seed-fly and rust are available but are limited in their effectiveness.
Cultivation & Scalping:
Competition: Competitive pasture species should be introduced after Bathurst Burr plants have been removed to prevent re-establishment.
Monitoring: Successful treatment programs rely on ongoing monitoring of sites. Regrowth and new seedlings can easily become larger infestations if follow-up treatments are not part of the management program


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Image Credit: Megan Power

Image Credit: Megan Power

Image Credit: Megan Power

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