The Folding Guides to trees of “trails and forests” emphasize the species you are most likely to see in a natural setting away from human development. Guides to trees of “towns and cities” emphasize the species that are most likely to be seen in yards and parks in developed areas. Many species are found in both guides, but the “towns and cities” guides include many exotic species that are commonly cultivated (such as Ginkgo, Callery Pear, etc), while the “trails and forests” guides include almost entirely native species. Most people will find the “towns and cities” guides more helpful for everyday use.