Willow pollen. Coloured scanning electron micro- graph (SEM) of a pollen grain of goat willow, Salix caprea. Also known as the pussy willow". This elongated pollen grain has a grooved and pitted surface. It's protein coat is distinctive of the willow genus (Salix). Pollen is produced by the male sex organs in flowers and dispersed to the female sex organ where the egg is fertilized. The protein coat is both highly characteristic and resistant to decay. Thanks to these properties, studies of ancient pollen like willow from deep soil samples has helped to reveal the history of European vegetation since the last ice age. Magnification: x800 at 6x6cm size."