Status of African thistle in Tasmania
- African thistle is a declared weed in Tasmania under the Tasmanian Weed Management Act 1999. The importation, sale and distribution of African thistle are prohibited in Tasmania.
- The legal responsibilities of landholders and other stakeholders in dealing with African thistle are laid out in the African Thistle Statutory Weed Management Plan.
What does African thistle look like?
thistle is a herbaceous to woody perennial (long-lived) herb growing
from 30 to 80 cm high. The stems can be upright or spreading and are
conspicuously wooly at the base. Stems can form roots where they touch
the soil. The leaves are wooly on the underside, stiff, with deeply cut
and spiny lobes. The flower head is made up of many yellow tubular
florets grouped into small terminal heads. The short thick rootstock
produces an extensive mat of roots and rhizomes (underground stems) in the surface soil layer.
germinate in autumn and young plants form a rosette of leaves.
Flowering occurs in late spring through summer. The above-ground growth
dies off in late summer and early autumn, with new growth developing
from the crown and rhizomes in late autumn.
African thistle is
spread when the spiny flower-head forms a burr which is picked up and
carried by passing animals. Seeds fall from the burr as it is carried or
rolled along. Colonies increase in area through rhizome growth and stem
Flowering African thistle, photo: Department of Agriculture and Food, Western Australia
copyright: V. Tyrer
Images above (left t right): African thistle; flowering plant, photo: V. Tyrer
copyright: V. Tyrer
Impacts of African thistle
- African thistle is unpalatable and dense infestations
can reduce pasture productivity and prevent access to beaches and
recreational areas. There is the potential for African thistle to spread
widely in Tasmania in coastal and inland areas.
Where does African thistle occur?
- African thistle is native to South Africa. African
thistle occurs at several ports in Western Australia, South Australia
and Victoria, probably as a result of seed being dumped in ballast
- African thistle established a population King Island, but has since been eradicated. African thistle has not naturalised elsewhere Tasmania.
What you need to do
- If you locate African thistle anywhere in Tasmania, or if you find a plant that you think could be African thistle, immediately contact your Regional Weed Management Officer on 1300 368 550 to report this weed.
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