The wildflowers in the book are arranged by both color and blooming date (within color classes), just as you’ll see in other field guides. However, in this guide, the flowers appear as they actually look when you see them from the road."The book is available here in a PowerPoint presentation. I particularly enjoyed the descriptive phrases such as "There are several closely-related fleabane species, though few people care which is which," and the "differential diagnosis," such as this for the stiff goldenrod:
Similar species:Via Neatorama.