Scanning electron microscope image of pollen grains from Helianthus annuus (common sunflower). This image is in the public domain. https://remf.dartmouth.edu/images/botanicalPollenSEM/source/10.html

Scanning electron microscope image of pollen grains from Helianthus annuus (common sunflower). This image is in the public domain. http://remf.dartmouth.edu/images/botanicalPollenSEM/source/10.html