Therefore, agriculturalists have made it a priority to address the widespread nature of poison hemlock. See Poison hemlock for more information. His execution consisted of drinking the poison hemlock and he died in 399 BC. Poison hemlock contains traces of other similarly poisonous alkaloids. Examples of highly toxic herbs include poison hemlock and nightshade. All water hemlock and poison hemlock are highly poisonous, but water parsnip is not. It resembles the highly toxic poison hemlock and water hemlock. For example, "Euodynerus foraminatus" paralyzes the larvae of the poison hemlock moth ("A. alstroemeriana"). Nevertheless, osha and poison hemlock can be found only a few feet from each other. The poison hemlock moth can be found wherever its host plant ("Conium maculatum") occurs. Poison hemlock ("Conium maculatum") contains highly toxic amounts of coniine. Poison hemlock grows quite tall, reaching heights of up to twelve feet (3.6 meters).