Bur buttercup is a short, flowering plant that may be invasive. It has caused fatal poisoning of sheep and other grazing animals.
Scientific name: Ceratocephalatesticulatus (previous genus Ranunculus)
Popular synonyms: curveseed butterwort
Distribution in the United States: western states primarily, extending to Illinois, Minnesota and New York
Toxic agent: ranunculin, which is metabolized to the toxic protoanemonin
Symptoms following ingestion:
(1) anorexia
(2) labored breathing
(3) diarrhea
(4) dyspnea
(5) weakness
Severe intoxications may be fatal.