This book is comprehensive and authoritative, but it is somewhat out of date. My chief complaint has to do with covers on this paperback book. The outside of the book cover is plasticized. If you set the book flat on a table at 50% humidity and normal room temperature, within a short time the cover will roll into a complete circle, making it difficult to handle and impossible to place another book on top. If you stand the book on its bottom edge, both covers will roll this way within minutes. For a moderately expensive paperback book, this is a substantial inconvenience. This type of cover was a poor choice for economy by the press of the Royal Botanic Gardens at Kew. Short of tearing the covers off of the book, I don't know how to make the book convenient for use. I can't honestly recommend this book unless you will be satisfied with a coverless book on your shelf.