False-colour scanning electron micrograph (SEM) of pollen grains germinating on the stigma of the opium poppy flower,Papaver somniferum. The stigma is the pollen receiving structure,which with the ovary,forms the female reproductive organ. It consists of ridges of finger-like projections in this species. The germinating grain swells,splitting to accomodate the emerging pollen tube. The tube,carrying the male gametes,grows down,around or into the stigma,down the style,enters the ovary & approaches the ovule (egg). The tip of the pollen tube ruptures,releasing the gametes (sperm) to fertilize the egg. Mag: X 145 at 35mm size. Coloured pink. Original is BW print B786/062 |