The book for scientifically interested readers who are contemplating the upcoming challenges of a rapidly growing world population. It clarifies the previously little-known benefits of so-called macrofungi. These are mushrooms that one typically encounters during walks in the woods and fields and can also be purchased commercially. How can macrofungi help save humanity? Can nutritional problems in poor African countries be solved with macrofungi? Is it possible to revitalize entire damaged forests? And what do mushrooms have to do with Mars? These and other intriguing questions are answered throughout the chapters. Readers gain insights into the secrets and workings of a science that, like fungi, operates in the background, whose significance is rapidly increasing, even though it has so far been recognized by relatively few researchers.