Among English speakers, A. bisporus is known by many names. A young specimen with a closed cap and either pale white or light brown flesh is known as a button mushroom or white mushroom. In strains with darker flesh, the immature mushroom is variously marketed as a cremini mushroom, baby portobello, baby bella, mini bella, portabellini, Roman mushroom, Italian mushroom, or brown mushroom. At this stage of maturation, the cap also may begin to open slightly. In maturity, the mushroom is called a portobello The French name is champignon de Paris ("Paris mushroom"). The spellings "pontobello", "portabella", and "portabello" are all used, but the first of these