Poison hemlock, fool’s parsley
Conium maculatum
Parsley (Apiaceae) Family

Poison Hemlock plant

Description: Poison Hemlock plantThe poison hemlock plant (also known as Beaver Poison, Herb Bennet, Musquash Root, Poison Parsley, Spotted Corobane, and Spotted Hemlock) is a biennial herb that may grow to 2.5 meters (8 feet) high. The smooth, hollow green stem may or may not be purple or red striped or mottled. Its leaves are finely divided and lacy, overall triangular in shape and grow up to 50 centimeters (20 inches) long by 40 centimeters (16 inches) wide. Tall, erect Poison Hemlock plant Its multiple, white, clustered flowers are small and grow in small groups that tend to form flat umbels. Its long, turniplike taproot is solid.  When crushed, the leaves emit a rank, unpleasant odor compared to that of parsnips.

This plant is very poisonous, and even a very small amount may cause death. This plant is easy to confuse with wild carrot or Queen Anne’s lace, especially in its first stage of growth. Wild carrot or Queen Anne’s lace has hairy leaves and stems and smells like carrot. Poison hemlock does not.

The poison is a neurotoxin which disrupts the central nervous system.  Ingestion in any amount can lead to respiratory collapse and death.  Death can be prevented by artificial respiration until the effects of the toxic compounds have worn off 48-72 hours later.

Poison Hemlock plantHabitat and Distribution: Poison hemlock grows in wet or moist poorly drained ground like swamps, wet meadows, stream banks, and ditches. It also appears on roadsides, edges of cultivated fields, and waste areas.  Native to Eurasia, it has been introduced to the United States and Canada.

Other Uses: Ancient civilizations used small amounts of Poison Hemlock for medicinal purposes.  The practice was very dangerous though as even small amounts can kill a person.

Grove of Poison Hemlock plants growing in the wild

Cultivated Poison Hemlock plant

Dried Poison Hemlock seeds on the plant

Side view of Poison Hemlock flowers

Poison Hemlock flowers

Top view of Poison Hemlock flowers

Top head of a Poison Hemlock plant

Close-up of Poison Hemlock flowers

Sometimes the green stems have red or purplish mottled finishes

Poison Hemlock plant growing in the wild

Close-Up of Poison Hemlock Leaves

Color drawing of Poison Hemlock plant illustrating the plant's stems, flowers, root system, and seeds

Color drawing of Poison Hemlock plant illustrating the plant's components and cross section of seed pods

Color plate of Poison Hemlock plant illustrating the various components of the plant's stems, leaves, flowers, and seeds