Before you go looking for leaves, visit the PA Department of Conservation and Natural Resources website to learn why autumn leaves change colors.


  • Audubon Guide Field guide with over 800 species of North American trees.   Free registration.
  • Leaf Tree ID Key Match your leaf to photos from the Wisconsin Center for Environmental Education
  • Leaf Snap Species Search photos to find your leaf. Designed by Smithsonian Institute, Columbia University and the University of Maryland.
  • Tree Identification Key Answer questions or view photos from the Michigan State University Extension.
  • What Tree Is It? Find your tree by its name, its leaf or its fruit. Designed by the Ohio Public Library.
  • What Tree is That? Answer questions to identify your tree on the Arbor Day Foundation site.


Once you’ve identified your tree, watch a video about it from the State University of NY, College of Environmental Science and Forestry.


Still puzzled about your leaf? Snap a picture and identify it with an App!

  • Audubon Trees App Carry your field guide with you with this free mobile app.
  • Leafsnap. Learn about your tree with this free mobile app developed by the Smithsonian Institute, Columbia University and the University of Maryland.
  • Virginia Tech Tree ID App Use this free mobile app to link to fact sheets for almost 1,000 woody plants.



The Audubon Society Field Guide to North American TreesNational Audubon Society FirstTrees of Pennsylvania TekielaPeterson First GuideTrees Trees identified by leaf





The Sibley Guide to TreesIdentifying TreesTrees of PennsylvaniaJust TreesTrees of Eastern North America

The illustrated encyclopedia of trees


National Wildlife Federation

Fall Color Woodland

Trees Allen J Coombes