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Western Wetland Flora

Field Office Guide to Plant Species

Poison-hemlock
Conium maculatum L.

JPG -- Species Photo JPG -- Distribution Map

Family:
Flowering: April-July
Field Marks: This species is distinguished by its tall stature up to 10 feet tall, its umbels of white flowers, its purple-spotted stems, and its much-divided leaflets less than 1/2 inch wide.
Habitat: Wet disturbed areas, particularly in roadside ditches.
Habit: Robust biennial herb with a taproot.
Stems: Upright, stout, branched, up to 10 feet tall, purple-spotted, smooth.
Leaves: Alternate, 3- to 4-pinnately compound, up to 18 inches long, finely divided into leaflets up to 1/2 inch wide, each leaflet deeply toothed or lobed, smooth.
Flowers: Borne in umbels, with many umbels per plant, each umber up to 3 inches across, subtended by small lanceolate bracts.
Sepals: 0.
Petals: 5, free from each other, white.
Stamens: 5.
Pistils: Ovary inferior, smooth.
Fruits: Ovoid, compressed laterally, up to 1/8 inch long, smooth, with pale brown ribs.
Notes: All parts of this plant are extremely poisonous when eaten. It is native to Europe and Asia.

Previous Species -- Western Water-hemlock (Cicuta douglasii)
Return to Species List -- Group 6
Next Species -- Sierra Corydalis (Corydalis caseana )

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Page Last Modified: Saturday, 02-Feb-2013 06:26:16 EST
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