Species Distribution Maps
Invasive and Noxious Weeds: USDA Plants-type in the scientific or common name in the top left corner and hit enter. The page that appears will have a map of the US distribution of the plant species near the bottom of the page and the option to look at the Illinois distribution on a county by county basis.
EDDMapS (Early Detection and Distribution Mapping System)-Click on "Distribution Maps" tab and choose between state and county distribution for the desired species.
New Invaders Watch Program- click on target species name to see its distribution map for northeastern Illinois