It is frequently found as a weed along roadsides, ditches and in waste areas. Poison hemlock was the source of poison with which Socrates was put to death. It contains several alkaloids which are chemically related to nicotine. The symptoms are similar to that produced by an overdose of nicotine. These alkaloids work by depressing the function of the central nervous system, causing paralysis.
Death occurs when the muscles used in breathing become paralyzed.
The tuberous roots may be mistaken for edible roots such as wild parsnip and wild artichoke. The toxicity of the plant is great and the active principle, cicutoxin, acts directly on the central nervous system. Symptoms appear from within 15 min. Excessive salivation is noted first, followed by spasmodic convulsions interspersed intermittently with periods of relaxation. Abdominal pain is evident.