Cereal plants are a type of grass that is grown for its edible grains. RYE, with three letters, is a cereal plant that is used to make bread, beer, and whiskey. MAIZE, with five letters, is a cereal plant that is also known as corn and is used to make tortillas, popcorn, and corn syrup. MILLET, with six letters, is a cereal plant that is used to make porridge and is also used as birdseed. BARLEY, with six letters, is a cereal plant that is used to make malt and is also used as animal feed. OAT, with three letters, is a cereal plant that is used to make oatmeal and is also used as animal feed.