Growth

Many species of mushrooms seemingly appear overnight, growing or expanding rapidly. This phenomenon is the source of several common expressions in theEnglish languageincluding 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.