Pollen

Colorized scanning electron microscope image of pollen grains from a variety of common plants: sunflower (Helianthus annuus), morning glory (Ipomoea purpurea), prairie hollyhock (Sidalcea malviflora), oriental lily (Lilium auratum), evening primrose (Oenothera fruticosa), and castor bean (Ricinus communis).
Pollen tube diagram

Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction.[1] It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells).

Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of gymnosperms. If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. Individual pollen grains are small enough to require magnification to see detail. The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and forensics.

Pollen in plants is used for transferring haploid male genetic material from the anther of a single flower to the stigma of another in cross-pollination.[2] In a case of self-pollination, this process takes place from the anther of a flower to the stigma of the same flower.[2]

Pollen is infrequently used as food and food supplement. Because of agricultural practices, it is often contaminated by agricultural pesticides.[3]

  1. ^ "Best and Worst Flowers for People With Allergies". WebMD.com. Retrieved 2023-10-30.
  2. ^ a b Chisholm, Hugh, ed. (1911). "Pollination" . Encyclopædia Britannica. Vol. 22 (11th ed.). Cambridge University Press. pp. 2–5.
  3. ^ Tosi, S.; Costa, C.; Vesco, U.; Quaglia, G.; Guido, G. (2018). "A survey of honey bee-collected pollen reveals widespread contamination by agricultural pesticides". The Science of the Total Environment. 615: 208–218. doi:10.1016/j.scitotenv.2017.09.226. PMID 28968582. S2CID 19956612.