Poison Hemlock

Conium maculatum L.

Apiaceae (Carrot Family)

▲ ▼ seedlings

▲ ▼ Young plants

Leaf ▲ ▼

▲ ▼ Spotted stems

▲ ▼ mature, flowering plants

▲ ▼ flowers

▲ young plants growing at base of past season's dried flowering stems

Colony of poison hemlock in June along roadside in pasture ▲

Conium maculatum L.; Poison Hemlock: (Bayer Code: COIMA; US Code COMA2)

Herbaceous biennial native to Europe
Produces large rosette of finely divided, fernlike leaves in fall of first year
Produces elongated, spotted (usually hairless or nearly so), flower stalk with multiple loose umbels of tiny white flowers
Flower stalk can grow 3-8 feet tall, sometimes taller
Appears very similar to Wild Carrot/Queen Ann's Lace:
- Wild Carrot has hairy stems, and leaves and has a carrot-like odor; dried flower heads fold up into funnel shape
- Poison Hemlock is nearly hairless; flowering stems smooth or waxy with purple spots; stems and leaves have a musky (mousy) odor; dried flower head remain open, flat
Entire plant is poisonous to consume; some people get contact dermatitis from foliage contact
Consuming very small amount of plant can be deadly to humans--leaves are most poisonous part
Also causes sickness in grazing livestock
Very common in southwest Missouri

(Updated January 15, 2019)