Poison hemlock works well to kill off any pesky philosophers, like Socrates (shown here), who might be corrupting the youth of the city-state. A native of Eurasia, poison hemlock's delicate flowers resemble Queen Anne's lace, but beware if the plant's stems have purple spots. Death or violent illness awaits foraging humans that mistake poison hemlock for a wild carrot or parsley, which hemlock's leaves resemble.
In Maine, one young man died after three bites of hemlock root in 1992, according to the Centers for Disease Control. In 2010, woman died after mistakenly tossing hemlock into her salad in Tacoma, Washington, reported KING5.com.