Spanish flag pollen. Coloured scanning electron micrograph (SEM) of a pollen grain of Ipomoea lobate (Spanish flag). I. lobata is a twining climber up to 5m tall, usually grown as an annual, with three-lobed leaves. The crimson-flushed stems bear one-sided racemes of small, tubular, dark red flowers which fade to orange and then a creamy yellow in summer. Pollen grains are the male sex cells of a flowering plant. Their characteristic surface is used by botanists to recognise and classify plants. Pollen in plants is used for transferring male genetic material from the anther of a single flower to the stigma of another in cross-pollination. In a case of self-pollination, this process takes place from the anther of a flower to the stigma of the same flower. Magnification: x320 when printed at 10cm wide.