David Auurora, the author of the book, taught a class at UCSF using the book as the text. I was fortunate enough to take it back in the 80’s. The book, in my opinion, was written for people who liked to eat wild mushrooms. Even when he wrote it there was confusion about some of the agaricus species which he discovered with stomach cramping on some and not the others. It’s very dated by npw I’m sure. There were no colorful pretty pictures. It was also oriented to the western United States. Since that class I’ve safely eaten wild mushrooms from California to Alaska.