When the mycelium hardens, truffles develop. The mycelium is a network of subterranean hyphae. Under normal conditions, these hyphae will develop into a mushroom. When the environment isn’t conducive to mushroom growth (due to drought, for example), the mycelium will create sclerotia. These sclerotia are also known as truffles. Truffles, like magic mushrooms, contain the hallucinogenic compounds psilocine and psilocybine. In the Netherlands, magic mushrooms are prohibited (as they are in many other countries). Truffles, on the other hand, vary from mushrooms in both technical and scientific terms. As a result, truffles may be freely grown, purchased, and eaten in the United States and Netherlands.