David Hewitt, Ph.D. – Philadelphia Trees: A Field Guide to the City and the Delaware Valley

https://www.barnesandnoble.com/w/philadelphia-trees-edward-s-barnard/1125196877

David Hewitt has been working with plants, animals, soils, and water for more than twenty-five years, starting when he began working on small farms in upstate New York. He has served in a variety of roles at a number of Philadelphia institutions, including the Wagner Free Institute of Science, and as a lecturer at the University of
Pennsylvania and a research associate in the Department of Botany at the Academy of Natural Sciences. He was an AAAS Science and Technology Policy Fellow in Washington, DC, working in agricultural policy. David has an A.S. from the Community College of Philadelphia, a B.A. in biology from the The University of Pennsylvania and a Ph.D. from the Department of Organismic and Evolutionary Biology at Harvard University.