Monkshood is found throughout the temperate zone of the Northern Hemisphere. Western monkshood is found at higher altitudes in the northern Rocky Mountain and Pacific Coast states.

Effects and Symptoms: The poison contained in monkshood can enter into the system through ingestion by mouth or absorbed through the skin. The first signs of monkshood poisoning appear almost immediately. They include burning and tingling; numbness of the tongue, throat, and face; followed by nausea, vomiting, blurred vision, prickly skin, paralysis of the respiratory system, gradual loss of vision, low blood pressure, slow and weak pulse, chest pain, giddiness, sweating, and convulsions. As the poison gradually spreads, the body temperature will gradually drop, producing a pronounced feeling of cold. The patient will feel as if there is ice water flowing through their veins. At the end, severe pain occurs, associated with the paralysis of facial muscles. Breathing is at first rapid, then slow, and finally there is respiratory arrest. Slow paralysis of the heart muscle causes death. Patients often remain conscious until the very end. Some victims complain of yellow-green vision and tinnitus. Death can occur as quickly as ten minutes after initial contact to a few hours.