Definition of exine in English:



  • The decay-resistant outer coating of a pollen grain or spore.

    • ‘A few grains were seen which had shed the exine and released a circular microgametophyte, although the actual process was not observed.’
    • ‘Orbicules may be attached to the exine of the pollen grains.’
    • ‘This study concentrates on these parameters using purified exines (sporopollenin capsules) prepared from pine pollen, which consist of a central capsule and two lateral sacci.’
    • ‘Short elongated elements occur on the orbicule wall, similar to those present on the pollen exine.’
    • ‘The final activity of these cells is to deposit their remaining cell contents onto the developing pollen exine, with the only remaining identifiable organelles at this stage being the mitochondria.’


Late 19th century: perhaps from ex- ‘out’ + Greek is, in- ‘fibre’.