This is really the only field guide to trees and shrubs of California, and I have found no other single volume that covers both trees and shrubs of California. Unfortunately, the book is only moderately helpful. The book is no well-organized; in particular, there are no page references in the keys, just references to either a genus or a species, which often forces you to go from one key, to the index, then to another key, back to the index, then finally to the species you're looking for. What a pain! The range maps are poorly done and hard to understand. The quality of the writing ranges from fair to mediocre -- this is a problem because not every species is illustrated, leaving you sometimes dependent on a hard-to-understand written description. There are a few color plates, but they are pretty useless, and could have been left out. The black-and-white illustrations are generally good. Yet with all the negatives, it's a book many people will find worth owning -- if, for example, you have an interest in willows, you will find that many tree field guides leave out half the species of willow because they get classed as shrubs not trees. I would not make this my primary field guide to trees and shrubs, but it is a useful secondary reference. ( )