Great resource to have for understanding mushrooms and figuring out identification. An early section shows the principal groups and the characteristics that differentiate them. There is also a great section on different description terminology along with example photos/illustrations. I'd say my favorite feature of the book is the giant pages with huge photos of actual mushrooms, lines are drawn to exact locations on the mushrooms pointing out exact identification criteria. Edibility is always discussed with obvious symbols from "choice edibility" to big red exclamation for "poisonous" and a red skull and crossbones for "deadly."