Mushrooms belong to the group of organisms called fungi. Unlike trees and other plants, in which the above-ground or visible parts usually are the largest parts, a mushroom is just the fruiting body of a bigger organism that is largely hidden from view. The major part of a mushroom is concealed beneath the soil surface or within decomposing materials such as rotting trees or leaves.
Poisoning by wild mushrooms is common and may be fatal or produce merely mild gastrointestinal disturbance or slight allergic reaction. It is important that every mushroom intended for eating be accurately identified