No book is going to teach you botany in a day — you have to get down on your knees and go face to face with the flora. But this one gets you further in an afternoon than any field guide will, because Elpel doesn’t start with species. He starts with families. Learn to see eight of them by their patterns — mint’s square stem and opposite leaves, mustard’s four petals in a cross and six stamens, the umbrella of the carrot family, the pea’s banner and keel — and you can walk into country you’ve never seen and still place most of what’s growing. It’s a way of thinking, not a list to memorize, which is why it works anywhere. He self-published it out of Montana, draws the plants himself, and folds in what’s edible and medicinal as he goes. Take it out and use it wrong a few times. That’s the day.