Noxious Weeds Profile - Poison Hemlock

• Pub 505 - all parts of the plant are poisonous.
• NE Weeds - Plants parts have a disagreeable odour when crushed. All aprts of the plant contain toxic alkaloids, including coniine, that cause respiratory failure in humans and other animals when ingested.
• Canadian Poison Plant - Cattle, goats, horses, swine, and sheep as well as rabbits, poultry, deer, and humans have been poisoned after ingesting poison-hemlock. Animal species vary in their susceptibility to acute toxicity (Keeler et al. 1980).
• Cornell Poison Plant - All plant parts are poisonous. However, the seeds contain the highest concentration of poison. The conium alkaloids are volatile and can even cause toxic reactions when inhaled.
• Indiana Toxic Plants: TOXICITY RATINGS: Moderate to high. ANIMALS AFFECTED: All animals may be affected. Grazing animals, swine and animals that may eat the seeds (especially poultry) are more at risk than pets. DANGEROUS PARTS OF PLANT: All parts, especially young leaves and seeds. CLASS OF SIGNS: Nervousness, trembling, incoordination, depression, coma, death, birth defects.

Growth Habit

• Seeds

• Ontario Weed Gallery: Poison Hemlock
• Ontario Vegetation Management Association