Apiaceae · Conium
Conium maculatum
10 states listed
State distribution — 10 / 50 states listed
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Listings by state
| State | Classification | Common Name Listed | Notes |
|---|---|---|---|
| Connecticut | Prohibited | Poison hemlock | |
| Delaware | Noxious | Poison hemlock | |
| Idaho | Class B | Poison hemlock | Restricted |
| Louisiana | Restricted Seed | Poison hemlock | Toxic seed |
| Maine | Prohibited | Poison hemlock | Do Not Sell List |
| Michigan | Prohibited | Poison Hemlock | Biennial/perennial |
| Ohio | Prohibited | Poison Hemlock | Biennial/perennial |
| Rhode Island | Invasive | Poison Hemlock | Biennial herb |
| West Virginia | Noxious | Poison hemlock | Biennial |
| Wisconsin | Restricted | Poison hemlock | Biennial |
Source
Data compiled from individual state Department of Agriculture noxious weed lists. Verify against current official state sources before regulatory use.
U.S. Noxious Weed Database, generated April 2026.