Kress W. John Kress 
Smithsonian Trees of North America [PDF ebook] 

An indispensable illustrated source of information for hundreds of species of North American trees This authoritative reference on native and non-native trees of North America, by Smithsonian veteran W. John Kress, provides an unprecedented appraisal of more than 325 common species. More than a field guide, it includes * over 300 range maps and 3, 000 photographs of leaves, flowers, fruits, seeds, and bark; * an in-depth introduction to the biology of trees, their value, structure, evolution, classification, ecology, and conservation; * descriptions of each species, organized by genus and family; * a reflection on the consequences of environmental change on the health of trees, now and in the future; * a presentation, based on the latest technologies, of North American trees in a planetary and evolutionary perspective. Smithsonian Trees of North America, ten years in the making, marries science and art to provide an insightful and compassionate exploration of the diversity, structure, form, and beauty of trees.