Pollen grains of flowering plants are protected because of a stable, rot‑resistant outer rind.

Pollen from a variety of common plants: sunflower (Helianthus annuus), morning glory Ipomoea purpurea, hollyhock (Sildalcea malviflora), lily (Lilium auratum), primrose (Oenothera fruticosa) and castor bean (Ricinus communis). The image is magnified some x500, so the bean shaped grain in the bottom left corner is about 50 ?m long.

Image: Dartmouth Electron Microscope Facility / wikimedia commons / Public Domain ‑ No restrictions

Scanning electron microscope image of pollen grains from Helianthus annuus (common sunflower).

Last Updated May 12, 2020