Lavatera pollen grains, coloured scanning electron micrograph (SEM). Lavatera or Mallow is a genus of herbaceous annual, biennial, and perennial plants in the family Malvaceae. It is one of several closely related genera in the family to bear the common English name mallow. The genus is widespread throughout the temperate, subtropical and tropical regions of Africa, Asia and Europe. Pollen grains are the male gametes (sex cells) of a 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: x800 when printed at 10 centimetres wide.