The Illinois Department of Natural Resources, Illinois State Museum and Illinois Natural History Survey have online resources that help with Illinois tree identification. Illinois' DNR has a webpage with photographs of common trees' leaves and nuts. Types of trees include black walnut, hackberry, pecan and swamp white oak.
The Illinois State Museum lists trees' common and scientific names. Each common name links to a pop-up window with further information. A map displays the counties where the tree grows. In addition, a photograph shows a small photo of a mature tree.
The Illinois Natural History Survey displays evergreen and deciduous tree names in a chart. Additional information includes each tree's natural habitat, the regions where it grows, its fruit type and special identifying features.