Back-scattered electron microscope image of pollen grains from Lilium auratum (oriental lily). This image is in the public domain. https://remf.dartmouth.edu/images/botanicalPollenSEM/source/3.html

Back-scattered electron microscope image of pollen grains from Lilium auratum (oriental lily). This image is in the public domain.
http://remf.dartmouth.edu/images/botanicalPollenSEM/source/3.html