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Poison Hemlock Conium maculatum


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Poison Hemlock
credit: William & Wilma Follette

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Family: Apiaceae, Carrot view all from this family

Description Biennial. Height: 5-8 ft tall. Habit: coarse. Smooth green stem, usually spotted or streaked with red or purple on its lower half. Flower: white umbel 4-6 in across. Large leaf up to 20 in long resembles parsley. Smooth white tap root resembles parsnips. Leaf and root have rank odor when crushed.

Warning All parts of this plant are deadly poisonous if eaten, containing the toxic alkaloid coniine (the first alkaloid synthesized in the laboratory). Children can be poisoned by blowing through whistles made from the stalks. Judging from the symptoms, it was an extract of this hemlock that was used to execute Socrates and others in ancient Greece. Death results from the eventual paralysis of the respiratory nerves, leading to suffocation. Sensitivity to a toxin varies with a personís age, weight, physical condition, and individual susceptibility. Children are most vulnerable because of their curiosity and small size. Toxicity can vary in a plant according to season, the plantís different parts, and its stage of growth; and plants can absorb toxic substances, such as herbicides, pesticides, and pollutants from the water, air, and soil.

Flower Late summer.

Habitat Mesic to hydric disturbed sites and open fields; stream banks.

Range Continental U.S. except Florida and Mississippi.

Discussion All parts of the plant are poisonous. Listed as a noxious weed in some states. Introduced from Europe. Also known as: cigue maculee, cigue tachetee, deadly hemlock, poison parsley.