The Arbor Day Foundation's What Tree Is That? is a unique tree field guide that uses a step-by-step approach to identify common trees. The scientifically illustrated, 164-page book helps readers identify more than 200 unique trees from across the United States and Canada. With just a few leaves from a tree, this easy-to-use field guide uses a series of questions and pictures to help classify the tree in question. This guide has proven to offer the simplest method for identifying trees, simple enough for a child to use yet often relied upon by tree experts.