ABSTRACT
The hemlocks, poison-hemlock and waterhemlock, are poisonous plants growing in pastures and on ranges throughout the United States. Poison-hemlock and waterhemlock are not considered high on the list of economically important poisonous plants on a national basis; however, they do cause devastating losses to individuals. Poison-hemlock is native to Eurasia and northern Africa and has been naturalized in most parts of the United States and Canada. Cattle bedded down near or in patches of poison-hemlock have been poisoned by eating it in the early morning. The relative toxicity of the plant to different livestock species and the teratogenic effects in offspring are variable. Producers should be cautious about grazing animals in areas where poison-hemlock has been treated. Poison-hemlock contributes to the overall livestock loss from poisonous plants, estimated to be over $100 million annually in the United States. Economic losses from waterhemlock are significant to the livestock industry every year.
