Maize (Zea mays). Watercolour artwork illustrating stages of growth of maize. The stem at the top is topped by spikelets of flowers, arranged on a raceme. Lower down are the ripening fruiting bodies called cobs, covered in individual yellow kernels, which are surrounded by leaf sheaths called husks. The fibrous structures at the tips of each cob are the female stigmas which are designed to catch pollen grains. Maize is one of the world's most important crops. It can be eaten as corn on the cob, sweetcorn or popcorn It can also be ground down to produce flour, distilled to make a whiskey and extracts can be used in the production of cooking oil and margarine. Maize is a good source of potassium and Vitamin A, and is high in fibre.