Scientific name: thesium australe

Other names: Toadflax, Southern Toadflax


  • Queensland: Vulnerable (EPBCA 1999)
  • National: Vulnerable (NCA 1992)


Austral toadflax is a small, straggling, perennial herb that grows to 40 cm tall. The herb has slender, hairless, yellowish-green wiry stems that are arranged alternately on the stem. The species has small, narrow, solitary flowers. The non-reproductive part of the flower is 2-3mm long and white in colour. The plant flowers mostly in spring and summer and produces an oval nut that is 2.5 mm long.

Where found

Austral toadflax is the only species of thesium that occurs in Australia. It has sporadic distribution, but is widespread between the Bunya Mountains in Queensland to north-east Victoria.

Austral toadflax is semi-parasitic on the roots of a range of grassland species, notably kangaroo grass. Usually thriving on damp sites, the austral Toadflax is also found in shrub lands, grasslands or woodlands at various altitudes.


  • Human disturbance and habitat loss
  • Grazing by livestock
  • Invasive weeds
  • Urban developments.


Austral toadflax is protected under the Nature Conservation Act 1992 and the Environmental Protection and Diversity Act 1999. It is an offence to damage or interfere with Austral Toadflax in any other way than when accepted by the respective Acts.

Redland City Council manages environmental weeds throughout the Redlands Cost to minimise their impact on native ecosystems and plants such as Austral Toadflax.

Did you know...?

You are most likely to find austral toadflax on open grassy heath, usually among kangaroo grass surrounded by eucalyptus woodlands and grasslands dominated by barbed-wire grass.

Coastal populations have been associated with plants including acacia sophorae or the banksia integrifolia.

How you can help

Manage environmental weeds on your property – see IndigiScapes’ brochure entitled Environmental Weeds of the Redlands [PDF, 60.0MB] or visit the centre for advice on how to remove them and stop them from spreading.

Record your sightings on the Atlas of Living Australia