The title pretty much sums up the contents. Essentially a book to commemorate the ca 100 year existence of the Arnold Arboretum, this book contains a wealth of historical material. My personal favorite is the story on the "One Millon Dollar Tree".
What the title does not describe is the illustrations. There are a few color photographs, but also some exquisite colored-in line drawings and a lot of historical black&white material in a variety of techniques. Obviously someone resisted the pressure to conform to a preset style and chose those pictures which best fitted the subject, regardless of current fashion.
Should be a favourite for tree-lovers everywhere!
P.S. The edition I have is the 1990 original, and I don't know the 1995 reprint.