Micropyle

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micropyle

[′mī·krə‚pīl]
(botany)
A minute opening in the integument at the tip of an ovule through which the pollen tube commonly enters; persists in the seed as an opening or a scar between the hilum and point of radicle.

Micropyle

 

(1) An opening in the membrane of the eggs of insects, arachnids, some mollusks, fishes, and a number of other animals, through which the spermatozoon penetrates. (2) An opening in the apex of the ovule in higher seed plants, through which the pollen tube penetrates during pollination. The micropyle is formed because the integuments surrounding the ovule are unattached.


Micropyle

 

the canal in the integument or integuments of a plant through which the ovule is penetrated in gymnosperms by pollen grains and in angiosperms by pollen tubes. The external opening of the micropyle may be observed on the surface of a mature seed in the form of a dark dot.

References in periodicals archive ?
6) shows how the ovule becomes inverted so that the micropyle points towards the cone axis, even though this axis may not extend above the insertion of the complex (Fig.
As a consequence the micropyle of any ovule points either horizontally or downwards, its orientation initially imposed by growth of the epimatium (Fig.
5c) cannot enter the micropyle because this is occluded by an extension of the nucellus, sometimes described as "stigma-like.