Roundish or “ovoid” in shape (depending on variety), nutritious walnuts have a hard wrinkled outer shell which is divided into two sections within the shell. Each section contains the fruit or nut, which some say the shape resembles the human brain. Botanically a seed, walnuts are from any tree in the genus Juglans. Walnuts can be consumed raw, roasted, or as nut butter. They are often a desired ingredient in many foods such as mueslis, baked goods, trail mixes, and energy bars.