Bathurst Bur

(Xanthium spinosum)

Total Control Pest

Bathurst Bur is a shrubby annual herb that grows to 1 metre high. It has well-branched, upright stems that are armed with triple spines grouped in opposite pairs. Flowers are inconspicuous, and fruits are bur-like, with hooked spines. They contain two seeds that are spread mainly by attachment to animals, by water, and in produce.

Reasons for the Strategy

The thin pointy dark green leaves of Bathurst Bur.

Bathurst Bur seedlings are toxic to cattle, goats, poultry, sheep and, in particular, horses and pigs. Burs and spines irritate the skin of shearers, devaluing wool, and the burs damage the feet of livestock. Contact with the plant causes dermatitis in some people. The plant competes strongly with summer crops, and preferred pasture species.

Bathurst Bur is assessed at “1” (long seed viability) on the infestation curve. There is only one active site in Nelson. The low incidence of Bathurst Bur in the Tasman-Nelson region, extensive areas of suitable habitat, and the potential for it to cause significant adverse effects, mean the benefits of total control far outweigh the costs.


To contribute to the eradication of Bathurst Bur by ensuring that all known sites in the Tasman-Nelson region are inspected annually and all live plants are destroyed during the term of the Strategy.

Alternative Measures

The alternative option of “do nothing” or relying on voluntary control will not achieve the objective of eradication, and will result in significant additional costs to the community with respect to lost production and the increased cost of control in the future.

Strategy Rule for Bathurst Bur

The occupier shall destroy all adult and juvenile forms of Bathurst Bur on land that they occupy. A breach of Strategy Rule 4.2.5 is an offence under Section 154(r) of the Biosecurity Act 1993.

Biosecurity Act Requirement

No person shall knowingly sell, propagate, breed, release, or commercially display Bathurst Bur, under Sections 52 and 53 of the Act.