The black walnut nut is a small, hard-shelled nut with a strong, distinctive flavor. It is encased in a thick, deeply grooved husk that is difficult to crack open. The nut itself is oily and has a rich, earthy taste that is often used in baking and cooking, particularly in desserts and as an ingredient in salads. It is known for its unique and robust flavor, which sets it apart from other types of walnuts.