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Tip of a tulip stamen with many grains of pollen
Closeup image of a cactus flower and its stamens
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 is a fine to coarse powder containing the microgametophytes of seed plants, which produce the 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 coniferous plants. 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. In a case of self-pollination, this process takes place from the anther of a flower to the stigma of the same flower.

The structure and formation of pollen

Triporate pollen of Oenothera speciosa
Pollen of Lilium auratum showing single sulcus (monosulcate
Arabis pollen has three colpi and prominent surface structure.
Pollens/Microspores of Lycopersicon esculentum at coenocytic tetrad stage of development observed through oil immersion microscope; the chromosomes of what will become four pollen grains can be seen.
Apple pollen under microscopy

Pollen itself is not the male gamete.<ref name="facts_and_practice_for_a_level">{{#invoke:citation/CS1|citation |CitationClass=book }}</ref> Each pollen grain contains vegetative (non-reproductive) cells (only a single cell in most flowering plants but several in other seed plants) and a generative (reproductive) cell. In flowering plants the vegetative tube cell produces the pollen tube, and the generative cell divides to form the two sperm cells.

Pollen sections
Intro  Pollination  Pollen in the fossil record  Allergy to pollen  Nutrition  Forensic palynology  See also  References   Sources   External links  

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