- the larger of the two kinds of spores characteristically produced by seed plants and a few fern allies, developing into a female gametophyte.Compare microspore.
- the embryo sac of a flowering plant.
Origin of megaspore
Related formsmeg·a·spor·ic [meg-uh-spawr-ik, -spor-] /ˌmɛg əˈspɔr ɪk, -ˈspɒr-/, adjective
First recorded in 1885–90; mega-
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for megaspores
Historical Examples of megaspores
The megaspores are, of course, very much larger than the microspores.
The germination of the megaspores is started in the sporangium; at a certain point in their development they are shed.
The number of microspores produced is very large, but only four megaspores are borne in each megasporangium.
The megaspores bear hooks, and in this way the two processes become attached.
British Dictionary definitions for megaspores
Derived Formsmegasporic, adjective
- Also called: macrospore the larger of the two types of spore produced by some spore-bearing plants, which develops into the female gametophyteCompare microspore (def. 1)
- the cell in flowering plants that gives rise to the embryo sac
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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Word Origin and History for megaspores
Online Etymology Dictionary, © 2010 Douglas Harper
- One of the two types of haploid spores produced by a heterosporous plant. Megaspores develop into female gametophytes and are usually larger than microspores.
The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.