Definition of pollen grain in English:

pollen grain

Pronunciation /ˈpälən ɡrān/ /ˈpɑlən ɡreɪn/


  • Each of the microscopic particles, typically single cells, of which pollen is composed. Pollen grains have a tough coat that has a form characteristic of the pollen-producing plant and which can still be recognized in some archaeological deposits.

    See also palynology

    ‘The pollen grain is the male gametophytic phase of flowering plants.’
    • ‘The pollen grain (male gametophyte) is a three-celled structure composed of two generative cells encased within the vegetative cell.’
    • ‘The transfer of the pollen grain (male gametophyte) from the stamen to the stigma initiates the processes that can result in fertilization.’
    • ‘A pollen grain was considered germinated if pollen tube length was greater than the diameter of the pollen grain.’
    • ‘Although this relationship may vary between species, for a particular species it is constant, indicating that the polarity of the pollen grain owes its origin to the topology of microspore tetrad formation.’