Author: Cheryl Haxen

Weeds are sometimes an annoyance and always have some economic effect on our agriculture. However, sometimes they have a devastating effect, forcing producers out of business, as in the case of this plant.

This is Pimelia, native riceflower, of which there are over 100 species on Australia. Some of the shower species are popular garden plants. The three serious pest species are shown in this post: Images 1 and 2 are P. simplex. Images 3, 4 and 5 are P. elongata, and 6-9 are P. trichostachya. (Credit for photos of live plants to https:/futurebeef.com.au from which much of the information about the significance of these plants is drawn. The site had excellent information for anyone interested in finding out more).

Toxins in these three species are responsible for a poisoning syndrome in stock. It is known as St. George disease, Maree disease or 'Big Head', and has serious consequences for sheep and horses which eat it, but particularly for cattle.

Animals become lethargic, suffer chronic diarrhoea, nasal dripping, and lymphoedema with swelling of neck, head and abdomen. The brisket beneath the head and the jaw also swells ('bottle jaw'). The liver and heart are damaged, with pounding of the heart reportedly being heard over some distance. There is no antidote or treatment, and sudden death of the animal often follows.

The plants are practically impossible to control or eliminate so cattle properties are sometimes obliged to destock, and the farmer sells up. This has certainly occurred in St George, which is about 350km West of Toowoomba.

The other common name for Pimelia is 'poverty weed'...an apt name to those who have been thus financially impacted.