Ann Rhoads and Timothy Block cover all of Pennsylvania's 195 trees, both native and naturalized. Each species is described in a concise, tabular format that includes the characteristics of leaves, branches, bark, flowers, and fruits. The authors discuss flowering and fruiting time, autumn leaf color, and the size of the largest specimen recorded within the state. Rhoads and Block further provide valuable historical, ecological, and economic information on each tree species, including how Pennsylvania's trees were used by Native Americans and early European settlers. At the Morris Arboretum of the University of Pennsylvania, Ann Rhoads is Senior Scientist of the Pennsylvania Flora Project, Timothy Block is Director of Botany, and Anna Anisko is Botanical Illustrator.