Water Hemlock "Cicuta"

Water hemlock "Cicuta" is considered to be the most poisonous plant growing in North America. All parts of the water hemlock are toxic and can cause death in as little as 15 minutes.

Water hemlock grows in marshy, swampy areas of meadows; and along banks of streams, pools, and rivers. Accidental poisonings usually occur when water hemlock is mistaken for edible plants such as artichokes, celery, sweet potatoes, sweet anise, or wild parsnip.

Water hemlock is a relatively tall plant measuring approximately 90-200 cm. in height. This wildflower has dome-shaped compound umbels of small, white, radially symmetrical flowers. Water hemlock has two types of leaves: large, prominently forked, toothed lower leaves and compound, upper leaves with small, lanceolate, coarsely-toothed leaflets. The stems are smooth, fibrous and robust and are finely patterned with vertical magenta streaks.

Signs and Lesions of Poisoning

• Nervousness
• Excessive salivation and frothing
• Muscle twitching
• Dilation of the pupils
• Rapid pulse
• Rapid breathing
• Tremors
• Violent convulsions, grand mal seizures
• Coma
• Death may occur as early as 15 minutes after a lethal dose is consumed
• Skeletal and cardiac myofiber degeneration and necrosis

Animals will eat water hemlock early in spring and graze on the green seed heads later in the season. The roots; however, are more palatable and animals have been poisoned when the roots are exposed by plowing or cleaning ditches or when animal tramp in the streambeds. The underground portions of the plant, especially the tuberous roots, are highly toxic and very dangerous. Green seed heads have caused death losses in cattle.

The toxic substance in water hemlock is cicutoxin, a highly poisonous unsaturated alcohol that has a strong carrot-like odor. It is found principally in the tubers, but is also present in the leaves and stems during early growth. Leaves and stems lose most of their toxicity as they mature; however, green seed heads are poisonous.

Even though water hemlock is extremely poisonous, it is used as a medicine for migraine headaches, painful menstruation, and worms in the intestines.