State Distribution (10 / 50 states)
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 |
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.