agar-mushrooms agaricus-bisporus appearance baby-bella baby-portobello brown brown-cap-mushrooms brown-mushroom caps chestnut-brown chestnut-mushroom cremini-mushroom dark dry edible fleshy folded folds food fresh fungi Gills Italian-brown Italian-mushroom mini-bella mushrooms original portabellini quality quantity raw Roman-brown-mushroom shape smooth soft stalk stem surface surfaces Swiss-brown-mushrooms table-mushroom tasty texture textures underside variations vegetable vegetables wrinkled