Morning glory pollen grain. Coloured scanning electron micrograph (SEM) of a pollen grain from a morning glory flower (Ipomoea sp.). The grain has a highly sculptured outer wall (exine), which may assist in its dispersal by improving its adherence to pollinating insects. The characteristic surface of a pollen grain is used by botanists to recognise and classify plants. Each pollen grain contains a male gamete (reproductive cell) that is intended to fertilise an egg or ovule (female gamete), and initiate the formation of a seed for a new plant.