Poison hemlock- Conium maculatum

Conium maculatum L.

Apiaceae (Carrot family)

MI Status

Non-native

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 June-August in Michigan, prolific producer of tiny (~2mm), oblong seeds with one flattened side and distinct ribs on the rounded side.

Reproduction

Seeds.

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

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