Pollen grain. Coloured scanning electron micrograph (SEM) of a pollen grain from a forget- me-not plant (Myosotis sp.). This is among the smallest of any plant pollen. There is great variation in the size, shape and surface texture of pollen. The outer wall (exine) is highly sculpted in many plants, which may assist in dispersal. Each pollen grain contains a male gamete, which fertilises the eggs or ovules, initiating the formation of plant seeds. Magnification: x12,300 at 6x7cm size.