Cocklebur (Xanthium)
This is found in waste places and the edges of ponds and rivers. Poisoning occurs when pigs eat the two-leaf seedling. The mature plant is unpalatable. The toxins cause depression, vomiting, weakness, rapid breathing, convulsions and lowered body temperature. Death occurs within a few hours. Lesions seen at post-mortem examination include ascites (liquid in abdominal cavity) and liver congestion and necrosis. Treat with mineral or sunflower oil by mouth.