Dandelion and horse chestnut pollen. Coloured scanning electron micrograph (SEM) of pollen grains from the dandelion (Taraxacum officinale, yellow and green) and the horse chestnut (Aesculus hippocastanum, brown). The horse chestnut pollen grain at upper right is germinating, with the brown inner material bursting through the orange exine (outer wall). The dandelion pollen has a much more intricate exine, with numerous large spines. These are usually to help the pollen grain attach to the body hairs of insects which feed at the flower. Pollen bears the male reproductive cells of plants. Magnification: x1,000 at 6x7cm size. x1500 at 4x5"~LANDSCAPE"