photo: Jan Samanek, State Phytosanitary Administration, Bugwood.org
Poison Hemlock (Conium maculatum)
 Joseph M. DiTomaso, University of California - Davis, Bugwood.org |
 John D. Byrd, Mississippi State University, Bugwood.org |
 Steve Dewey, Utah State University, Bugwood.org |
 Jan Samanek, State Phytosanitary Administration, Bugwood.org |
 Jan Samanek, State Phytosanitary Administration, Bugwood.org |
Form:
Herbaceous biennial, 3 to 10 feet tall, moist and shady areas.
Leaves:
Alternate, compound, 8 to 16 inches long, oblong-triangular in outline, fernlike, hairless, emits unpleasant odor when crushed.
Flowers:
Spring, small, 5 white petals, in flat-topped umbels.
Fruits & Seeds:
Late summer; light brown, barrel-shaped capsules with conspicuous longitudinal ribs.
Roots:
Thick taproot, up to 0.75 inches in diameter.
Stem:
Stout, hairless, hollow except at the nodes, reddish-purple mottling.
Similar Species:
Common Cowparsnip (Heracleum maximum)
Great Angelica Angelica atropurpurea
Tier 3 - Presence is of Interest
The species that occur in this tier are likely ornamental escapes. It is not known whether they are established and/or spreading within Cleveland Metroparks. The ecological impact is poorly known for these species.
Action: The presence of these plants should be recorded by approximating the number of plants. Initial population numbers are likely small.
