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Cicuta douglasii
Also called Douglas' Water Hemlock, Douglas' Waterhemlock, Water Hemlock
Western water hemlock is a very poisonous perennial wetland plant native to western North America. It is not grown as a garden or houseplant, and it should be avoided and removed where it appears.
Cicuta douglasii, the western water hemlock, is a very poisonous perennial plant in the family Apiaceae.
The main distinguishing characteristic of western water hemlock is its toxicity. Cicutoxin is the toxin that is produced, making water hemlock the most poisonous plant in North America. Cicutoxin is a yellowish liquid that is prevalent in the roots. This unsaturated alcohol has a major impact on the central nervous system of animals. Early symptoms of cicutoxin poisoning include excessive salivation, frothing at the mouth, nervousness, and incoordination. These symptoms can progress to tremors, muscular weakness, seizures and respiratory failure. Ingestion of green materials of western water hemlock in amounts equivalent to about 0.1% of a person's body weight can even lead to death. In addition to being extremely hazardous to humans, this plant has an enormous impact on animals. As little as 0.2–0.5% body weight for sheep, 0.1% body weight for cattle, 0.5% body weight for horses, and 0.3% body weight for swine can be lethal. Death can occur within fifteen minutes of ingesting the toxin. It is one of the first plants to emerge in springtime, and has a very appealing odor.
Water hemlock is most abundant in British Columbia, and is indigenous to North America, where it grows primarily from the base of the Rocky Mountains to the Pacific coast, stretching from Alaska all the way to California. Water requirements limit this plant from inhabiting open rangelands. It grows in wet places such as marshes, stream banks, slough margins, ditches, meadows, and wet pastures.
Bulblet-bearing water hemlock · Spotted water hemlock · Mackenzie's water hemlock · Water hemlock
Text excerpted from the Wikipedia article Cicuta douglasii by its contributors, under CC BY-SA 4.0; the excerpts and the care summary drawn from them are shared under the same licence.
The care summary was written by AI (Claude, Anthropic) from the sources on this page, with general growing knowledge where they are silent. Check before relying on it.
Life form, climate and native range: World Checklist of Vascular Plants, Royal Botanic Gardens, Kew (CC BY 3.0), reformatted; see Plants of the World Online.
