Poison Hemlock

Conium maculatum

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Poison Hemlock - Very tall biennial that can grow up to around 12 feet in height. Stems will have purple splotches that help with identification.

Leaves: Leaves are fern-like, toothed and finely divided. Look very similar to wild carrot leaves.

Flowers: Flowers bloom from April-August. Flowers are small, white, and occur in 4–8-inch umbrella-shaped clusters.

Habitat: Plant is highly adaptive, but prefers rich, moist soil.

Weed Classification: B Select

Why is it a Noxious Weed?

The entire plant is toxic to animals and humans. Contains poisonous alkaloids, such as coniine. Poison Hemlock can spread quickly and infest large areas.

Poison Hemlock should not be burned, due to the toxins. Animals should not be allowed to graze even after it is cut or dried. Be cautious with any control efforts and wear gloves and protective clothing.

Control Recommendations:

WA State Noxious Weed Board

PNW Pest Management Handbook

UC Davis Weed Report