Agaricus bisporus is an edible basidiomycete mushroom native to grasslands in Europe and North America. It has two color states while immature—white and brown—both of which have various names. When mature, it is known as portobello mushroom, often shortened to just portobello. A. bisporus is cultivated in more than seventy countries, and is one of the most commonly and widely consumed mushrooms in the world.