poison hemlock

poison hemlock, lethally poisonous herbaceous plant (Conium maculatum) of the family Umbelliferae (parsley family). It has rank, finely divided foliage, flat-topped clusters of small white flowers, and a hollow, purple-mottled stem. Although native to the Old World, it is now naturalized and common in parts of the United States. The poisonous principle (the alkaloid coniine) causes paralysis, convulsions, and eventual death. Poison hemlock was used in ancient Greece in executions; a famous example was the philosopher Socrates. The related water hemlock (any species of Cicuta) is similar in appearance and as poisonous. C. maculata, called also musquash-root, spotted cowbane, and beaver poison, is the common species of E North America. The evergreen trees called hemlock are unrelated. Poison hemlock is classified in the division Magnoliophyta, class Magnoliopsida, order Apiales, family Umbelliferae.

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poison hemlock

Any of several poisonous herbaceous plants of the parsley family, especially Conium maculatum, believed to be the plant that killed Socrates. It is now common in the U.S. as well as in Europe. A tall biennial, this plant has green stems spotted with red or purple, large compound leaves, and white flowers. Though the poison is concentrated in the seeds, the entire plant is dangerous to livestock when fresh. Despite their common name, poison hemlocks are not conifers (see hemlock). Water hemlocks (Cicuta species) are similar and also dangerous.

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poison hemlock [′pȯiz·ən ′hem‚läk]

(botany)

Conium maculatum.A branching biennial poisonous herb that contains a volatile alkaloid, coniine, in its fruits and leaves.