Tar vine
Tar vine (Boerhavia coccinea) is found throughout Australia, with the exception of Tasmania. It is a common summer weed species and like most summer weeds it depletes soil moisture and nutrients, reducing the yield potential of the subsequent crop. Tar vine also acts as a green bridge for crop pests and disease. It can be a beneficial and highly palatable pasture species.
The origin of this species is unknown, but it may be native to the Kimberley, Pilbara and desert regions of Western Australia. There are twelve species of Boerhavia in Australia, but B. coccinea is the most common in disturbed areas like agricultural fields or roadsides. It is a common summer weed species and like most summer weeds it depletes soil moisture and nutrients, reducing the yield potential of the subsequent crop. This weed also acts as a green bridge for crop pests and disease, including scab disease, melon viruses, Xylella fastidiosa disease of grapes and plague locusts. It can be a beneficial and highly palatable pasture species. Some species of Boerhavia are consumed by people, but B. coccinea should not be harvested for human consumption. Leave it for the stock to eat. While tar vine contains oxalates, the levels are unlikely to be high enough to be toxic to livestock. However, livestock should be removed if toxicity is suspected. Tar vine has sticky seeds, which may contaminate wool. This weed is difficult to control, as the stressed, dusty plants are poorly responsive to herbicides.
For further information refer to Tar vine.