A comprehensive illustrated guide to the lichens of North America - Explores more than 400 species of lichens, alongside full-color photos - Shows the ways that indigenous peoples of North America have traditionally used lichens for food, clothing, dye, paint, and medicine - Explains in detail the scientific research behind the potency of lichen chemicals to heal many human conditions Lichens--a symbiosis of fungi, algae, bacteria, and yeast--can grow on nearly any surface and thrive in an extremely wide range of environments, including on the International Space Station. Used for millennia by Indigenous people, lichens are now being recognized by modern science for their unique medicinal potential, particularly against antibiotic-resistant bacteria, viruses, cancer, diabetes, and cardiovascular disease. In Medicinal Lichens, Robert Dale Rogers explores more than 400 species of North American lichens, including full-color photographic examples. He explains how lichens are members of the Fungi kingdom and, surprisingly, more biologically related to humans than to plants. He looks at what types of lichens we can find in geographic regions and habitats and shows how lichens are an indicator species, revealing the health of the environment and neighboring life forms, including that of humans. Rogers also explores each lichen chemical's healing properties, showing how pharmacological researchers are rediscovering the ancient wisdom of lichens long known by Indigenous peoples. Showcasing the benefits as well as the beauty of lichens, this book demonstrates how lichens are the perfect example of strength, cooperation, and harmonious living--Indigenous wisdom with the power to inform our modern way of life.