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