Noxious Weeds Profile
- Poison Hemlock
- English - poison hemlock
- French - ciguë maculée
- Latin - Conium maculatum L.
Poison hemlock (A - plant before flowering;
B - inflorescence of several compound umbels).
- Ontario Weeds Act - noxious
- Other provinces - noxious in Quebec
- Canadian Federal Seeds Act - Class 1
- U.S. Federal Noxious Weed - no
- U.S. Noxious State Reg - 7 states (including Ohio)
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.
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
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,
- Occasionally found along roadsides and woodlots. In early
80's was spread in Ontario in a seedlot of alfalfa.
- Not listed on any herbicide labels. Best control is by cutting
or pulling and destroying the plant residue
- One of the more toxic members of the carrot family.
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