This is one great book. I've had it for years. Granted it's an older book, so some material is dated, but much of it is timeless!
This book covers everything from the early development of irises, to culture and propagation, to insect pests and diseases, to novelty iris, to a couple of super chapters discussing the pigments of Iris and Iris Genetics.
Also this book designates one whole chapter to each of the various iris within the Genus Iris. Very informative and enlightening.
Another great feature in this book, are the drawings, charts, black and white photos, as well as color photos, you will find through out the book, making for good reference. A good book for those new to iris, as well as those who have been growing irises for years and years.