Fungi are overwhelmingly hidden – under the earth or inside other organisms. With their caps, tubes, and bulbs, they show us at the most their organs of reproduction. In homeopathy too, there are only a few visible representatives of this natural kingdom. Situated somewhere between plants and animals, the fungi are difficult to classify. Yet their effect on people is very interesting, whether as gut symbiont or agent of disease, as intoxicant or drug, as food or poison. This spectrum of action promises a wide range of homeopathic applications, which have so far been greatly underutilized. With new remedy provings, miasmatic connections and interesting case histories, our group of international authors will describe the magical kingdom of Agaricus, Bovista and Secale in homeopathic terms – from simple yeasts and lichen to the massive organisms of the higher fungi. The articles as a whole illustrate this complex natural kingdom. With this issue SPECTRUM presents a further, especially fascinating chapter of its modern, living materia medica.