Ragweed pollen. Coloured scanning electron micro- graph (SEM) of pollen grains (pink) on the stigma (green) of a ragweed plant (Ambrosia sp.). These spiky pollen grains contain the male sex cells of the plant. The multi-lobed stigma,the surface of the flower's female sex organ,the carpel,is where the pollen germinates. Ambrosia sp. is a daisy-like flower which grows in bare and waste ground. Its pollen is wind-borne and released in great quantities for cross-pollination. Ambrosia sp. pollen acts as an allergen causing hay fever (allergic rhinitis or pollinosis) in susceptible individuals. Magnification: x150 at 5x7cm size. Magnification: x75 at 35mm size | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Biophoto Associates |
Bildgröße: | 4583 px × 3079 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: |
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