Birch pollen. Coloured Scanning Electron Micrograph (SEM) of two birch tree pollen grains. The pollen grains show the distinctive round, sculpted protein coat of birch (Betula sp.). The raised pores, through which the pollen tube grows, are clearly visible. Pollen is produced by the male sex organs in flowers and dispersed to the female sex organ where the egg is fertilised. The protein coat is highly characteristic and extremely resistant to decay. Because of this, studies of pollen samples including birch from very deep soil samples have helped to reveal the history of European vegetation since the last ice age. Magnification x1400 at 6x7 cm size.