EDDMapS: www.eddmaps.org

EDDMapS is a web-based mapping tool to help locate and report invasive species infestations all over the US. It was developed by the Developed by The University of Georgia - Center for Invasive Species and Ecosystem Health to help Exotic Pest Plant councils to develop complete invasive species distribution data.

The EDDMapS website provides information on invasive plant and animal species, distribution of species by state and county, access to point data for GIS, statistics, and educational and control resources. 

Example: Counties where the tree of heaven is present in North Carolina.

Source: EDDMapS. 2011. Early Detection & Distribution Mapping System. The University of Georgia - Center for Invasive Species and Ecosystem Health. Available online at http://www.eddmaps.org/; last accessed August 23, 2011.