I just spent all day with this book, using it in the field and in the lab with my plant ecology students (undergraduates). I know that Sphagnum identification is difficult but the students found the random access key to 27 species very easy to use . It is much easier to use the key in the lab with a dissecting microscope and some dissecting tools than in the field. However the photographs are useful and the species descriptions are very complete. The book starts off with excellent chapters on the natural history, anatomy and ecology of Sphagnum.