poison hemlock

Poison hemlock- Conium maculatum

Conium maculatum L.

Apiaceae (Carrot family)

Life cycle

Biennial, spending year one as a rosette and then growing vertically in year two to produce flowers.

Leaves

Lacey or finely-dissected leaves (similar to wild carrot, except without hairs on the leaf surfaces)

Stems

Erect, hollow, purple spots help distinguish this species from other look-alikes, heights of 6-10 feet during the second year of growth (while flowering) with numerous branches.

Root

Taproot.

Flowers and fruit

White umbelliferous flowers (umbrella like, similar to wild carrot), appear July-September in Michigan, prolific producer of tiny (~2mm), oblong seeds with one flattened side and distinct ribs on the rounded side.

Reproduction

Seeds.

 

More information & control options 

 

poison hemlock at beal
Poison hemlock specimen at Beal Botanical Garden

 

Poison hemlock leaf
Lacey poison hemlock leaf
Andrea Moorman Poison hemlock
Hollow poison hemlock stem. Photo by Andrea Moorman
TrishaMaxwellPoisonHemlock
Purple spots along the stem are a distinguishing characteristic of poison hemlock. Photo by Trisha Maxwell

 

 

Tags: biennial, msu plant & pest diagnostics


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