Portobello Mushroom

Agaricus bisporus, known as table mushroom, cultivated mushroom or button mushroom, is an edible basidiomycete fungus which naturally occurs in grasslands, fields and meadows across Europe and North America, though has spread much more widely and is one of the most widely cultivated mushrooms in the world. The original wild form bore a brownish cap and dark brown gills but more familiar is the current variant with a white form with white cap, stalk and flesh and brown gills.
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Also Portobella. A full grown cremini mushroom (a variation of regular button mushrooms). The name 'portobello' began as a marketing ploy in the 1980's . Portobellos can easily measure 6 inches in diameter and have an open, flat cap. They have an earthy meaty flavor great in sandwiches and salads. They can be found in most produce sections.