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nucellus Line breaks: nu|cel¦lus
Pronunciation: /njuːˈsɛləs/

Definition of nucellus in English:

noun (plural nucelli njuːˈsɛlʌɪnjuːˈsɛliː)

The central part of an ovule, containing the embryo sac.
Example sentences
  • In addition, the grains were observed to float in water with sacci uppermost, consistent with the suggestion that distally placed sacci serve to orientate the germinal furrow of the pollen grain towards the nucellus of an inverted ovule.
  • Ovules consisted of an outer integument that surrounded the inner integument to form the micropyle, with the inner integument surrounding the nucellus and embryo sac.
  • Diboll and Larson report that there are no plasmodesmata connecting the nucellus to the embryo sac.


Late 19th century: modern Latin, apparently an irregular diminutive of nucleus.



Example sentences
  • Most of the wheat consumed by humans is processed from white flour, which is produced by milling to remove the germ and bran (pericarp, testa, nucellar layer, and aleurone layer).
  • Such grains frequently had a portion of the pollen tube outside the nucellar tissue so that the grains were held at an angle some distance from the nucellus.
  • A nucellar dome has been formed in the massive nucellar cap and the integument has overgrown the nucellus and formed a wide-open micropyle.

Definition of nucellus in:

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