Poison hemlock (Conium maculatum) is an invasive plant. It is a native of Europe, Asia and Africa and was first detected in West Virginia in 1939.
Poison hemlock is a tall biennial. It has leaves and white flowerheads resembling those of parsnips, carrots, and water hemlock. All parts of poison hemlock are poisonous. Poison hemlock commonly occurs in sizable stands of dense, rank growth along roadsides, field margins, ditchbanks and in low-lying waste areas. Once it is firmly established under such conditions, hemlock can preclude most other vegetation and established pastures.
For more information about this plant pest, see the CABI data sheet.