Primrose stigma. Coloured scanning electron micrograph (SEM) of the stigma (yellow) and style (lower left) of a primrose flower (Primula sp.). This is the top part of the female reproductive structure (carpel) of the flower. Pollen grains containing the male sex cells land on the stigma and may move down the style into the ovary (not seen). If the male cells fertilise the female sex cells (ovules) in the ovary, then the carpel may ripen to form a fruit that contains the plant's seeds. Magnification: x180 at 6x7cm size.