A wide variety of human-disturbed areas
Native to Eurasia; widespread across the United States
No listed status
This species is
to the Truckee Meadows.
Poison hemlock is a perennial plant that can grow around 5 to 8 feet tall. Their pinnate leaves have two-to-four leaflets, giving the leaves a lacy texture. Usually spotted or streaked with red or purple on the lower half of the stem, all parts of poison hemlock are hairless. Their white flowers form in clusters of umbles, which look like umbrellas.
As their name suggests, all parts of poison hemlock are extremely poisonous to livestock and humans. Poison hemlock contains an alkaloid poison called coniine which can cause respiratory collapse and death.
Poison hemlock grows in damp areas. It is used as food by the larvae of some Lepidoptera species (like butterflies and moths).
Poison hemlock is in the same taxonomic family as carrots (Apiaceae), which is one reason why plant identification is so important if you ever plan on foraging in the wild! This would be a deadly mistake to make.
In ancient Greece, hemlock was used to poison condemned prisoners. This was thought to be a form of a humane death sentence. Poison hemlock is thought to be the plant that Socrates was forced to consume in 399 BCE.
Ray S. Vizgirdas and Edna M. Rey-Vizgirdas, Wild Plants of the Sierra Nevada, 2009, book.
Carnegie Museum of Natural History, Poisons of the Carnegie: Hemlock, 2020, https://carnegiemnh.org/poisons-carnegie-hemlock/
Encyclopædia Britannica, Poison Hemlock, 2021, https://www.britannica.com/plant/dicotyledon
U.S. Forest Service - Weed of the Week, Poison Hemlock, 2006, https://www.invasive.org/weedcd/pdfs/wow/poison-hemlock.pdf
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