Book excerpt: In this field guide to the future, esteemed Harvard University botanist Peter Del Tredici unveils the plants that will become even more dominant in urban environments under projected future environmental conditions. These plants are the most important and most common plants in cities. Learning what they are and the role they play, he writes, will help us all make cities more livable and enjoyable. With more than 1000 photos, readers can easily identify these powerful plants. Learn about the fascinating cultural history of each plant.