Caption: Buttercup flower (Ranunculus sp.), coloured scanning electron micrograph (SEM). The pistil (centre) is surrounded by the stamens. The pistil is the female reproductive structure of the flower that comprises the ovary and style and stigma. The stamen is the male reproductive structure composed of a filament and an anther. The anthers produce pollen grains (not seen), each containing a male reproductive cell (gamete). Pollen is transferred to the pistils of another buttercup plant, fertilising it and initiating seed production.