megaspore

[meg-uh-spawr, -spohr]
noun Botany.
  1. 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.
  2. 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. 2018

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
  1. 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)
  2. 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]
  1. 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.