A mushroom is an above-ground fruiting body (that is, a spore-producing structure) of a fungus, having a shaft and a cap. By extension, it designates the entire fungus producing the fruiting body of such appearance, the former consisting of a network (called the mycelium) of filaments or hyphae. In a much broader sense, mushroom is applied to any visible fungus, or especially the fruiting body of any fungus, with the mycelium usually being hidden under bark, ground, rotten wood, leaves, etc. The main types of mushrooms are agarics (the button mushroom, the most common mushroom eaten in many western countries), boletes, chanterelles, tooth fungi, polypores, puffballs, jelly fungi, coral fungi, bracket fungi, stinkhorns, and cup fungi.