Rose stamens. Coloured scanning electron micrograph (SEM) of stamens in a Garden Rose flower, Rosa sp. Stamens are the male reproductive organs of the flower. They consist of a stalk-like filament (green) and a swollen anther (yellow). The anther is made up of pollen sacs from which tiny pollen grains (the male reproductive spores) are seen emerging through a longitudinal slit (at left). The pollen grains in the rose plant are picked up by insect pollinators and spread to the female stigmas. Pollen grains contain the male gametes that fertilize the female ovule to form a seed. Many stamens are to be found in each rose flower. Magnification: x20 at 6x7cm size. Magnification: x48 at 12x16cm size.