It is a kidney- or heart-shaped achene, in any normal variety. Its color varies from bottle green to grayish brown (dried fruit). It is attached to the end of a fleshy footstalk or peduncle, which is in fact the receptacle of the flower, that is, broadened and swollen, and forms the false fruit. It consists of an edible kernel, surrounded by two shells. The outer shell is smooth and of a bright brown color. Between the two shells, there is a very caustic oily substance. The cashew kernel is considered to be of high nutritive quality, and is covered with a thin reddish brown skin or testa.The cashew tree is large and evergreen, growing to 14 metres (46 feet) tall, with a short, often irregularly shaped trunk. The leaves are spirally arranged, leathery textured, elliptic to obovate, 4–22 centimetres (11?2–83?4 inches) long and 2–15 cm (3?4–6 in) broad, with smooth margins.