megaspore

[meg-uh-spawr, -spohr]
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noun Botany.

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

First recorded in 1885–90; mega- + spore
Also called macrospore.
Related formsmeg·a·spor·ic [meg-uh-spawr-ik, -spor-] /ˌmɛg əˈspɔr ɪk, -ˈspɒr-/, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for megaspores

Historical Examples of megaspores

  • The megaspores are, of course, very much larger than the microspores.

    How to Know the Ferns

    S. Leonard Bastin

  • The germination of the megaspores is started in the sporangium; at a certain point in their development they are shed.

    How to Know the Ferns

    S. Leonard Bastin

  • The number of microspores produced is very large, but only four megaspores are borne in each megasporangium.

    How to Know the Ferns

    S. Leonard Bastin

  • The megaspores bear hooks, and in this way the two processes become attached.

    How to Know the Ferns

    S. Leonard Bastin


British Dictionary definitions for megaspores

megaspore

noun

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
Derived Formsmegasporic, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for megaspores

megaspore

n.

1857, from mega- + spore.

Online Etymology Dictionary, © 2010 Douglas Harper

megaspores in Science

megaspore

[mĕgə-spôr]

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.