Poisonous plant found in S.E. Australia. Unpalatable to horses normally it can dominate in degraded pastures and may be consumed when pasture is very sparse or as a contaminant of hay. Growing to 1.2M high it has dark green leaves hairless on top and hairy below with bright yellow flowers in clusters in summer.
The toxin is a pyrrolizidine alkaloid which is reduced by drying (haymaking) but not eliminated. Toxicity is mainly confined to the liver with necrosis of liver cells resulting in jaundice, depression, loss of appetite and failure to grow and thrive. Brain damage secondary to liver failure may result inn nervous symptoms including head pressing, yawning, wandering and disorientation. In chronic poisoning secondary photosensitization may occur on exposed skin, particularly hairless and white areas with reddening, exudation of serum and crust formation. Treatment depends on the degree of liver damage but is largely supportive and may be ineffective once the disease is diagnosed and if liver damage is severe.
Other plants containing the same type of toxin include Patterson’s Curse (Salvation Jane) Fireweed, Comfrey, and Rattlepod (Crotalaria species)