Illinois Based Tree Identification Sites:
Chicago Botanic Gardens-Illinois' Best Plants
University of Illinois UI Plants
Tree Identification Links from Other States
University of Connecticut's Plant Index
Iowa State University's Interactive Key
Ohio Division of Forestry “What Tree is it?
Oregon State University's Trees of the Pacific Northwest. This site has a mystery tree challenge good for a home schooling exercise in using a tree identification key.
National Plant Databases
Arbor Day Foundation’s On-Line step-by-step “What Tree is That?
Silvics of North America
National Plants Database
Mobile Phone App
LEAFSNAP free mobile phone app using visual recognition to help identify tree species from photographs of their leaves. The app was developed by researchers from Columbia University, the University of Maryland and the Smithsonian Institution.
USDA Field Guide Common Macrofungi in Eastern Forests and Their Ecosystem Functions