For an older book - - it is quite indepth. All drawings and photographs are in black and white. This book discusses everything from companion plants, to culture, to progression of bloom, to hybridizng, to backgrounds of some of the first hybridizers.
Not only does this book cover Tall Bearded irises, but also the Median irises, Arilbreds, Beardless irises, and the bulbous irises.
My favorite part was the chapter where they discuss crossing between species. Yours may be the chapter where they discuss pests and diseases, or using irises in a rock garden.
It is written well and easy to understand. A lot of material is covered and you are sure to learn something new.