A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source.
Many species of mushrooms seemingly appear overnight, growing or expanding rapidly. This phenomenon is the source of several common expressions in the English language including "to mushroom" or "mushrooming" (expanding rapidly in size or scope) and "to pop up like a mushroom" (to appear unexpectedly and quickly). In reality all species of mushrooms take several days to form primordial mushroom fruit bodies, though they do expand rapidly by the absorption of fluids.
Edible mushrooms are used extensively in cooking, in many cuisines (notably Chinese, European, and Japanese). Though mushrooms are commonly thought to have little nutritional value, many species are high in fiber and provide vitamins such as thiamine, riboflavin, niacin, biotin, cobalamins, ascorbic acid. Though not normally a significant source of vitamin D, some mushrooms can become significant sources after exposure to ultraviolet light, though this also darkens their skin.Mushrooms are also a source of some minerals, including selenium, potassium and phosphorus.
Mushrooms that have psychoactive properties have long played a role in various native medicine traditions in cultures all around the world. They have been used as sacrment in rituals amied at mental and physical healing, and to facilitate visionary states. One such ritual is the velada ceremony. A practitioner of traditional mushroom use is the shaman and curandera (priest-healer).