Corn is a tall annual cereal grass (Zea mays) that is widely grown for its large elongated ears of starchy seeds. The seeds, which are also known as corn, are used as food for humans and livestock and as a source of biofuel and can be processed into a wide range of useful chemicals. Its protein is of poor quality, and it is deficient in niacin. Diets in which it predominates often result in pellagra (niacin-deficiency disease). Corn is high in dietary fibre and rich in antioxidants.