the larger of the two types of spore produced by some spore-bearing plants, which develops into the female gametophyte
Compare microspore (sense 1)
2.
the cell in flowering plants that gives rise to the embryo sac
Derived forms
megasporic (ˌmegaˈsporic)
adjective
megaspore in American English
(ˈmɛgəˌspɔr)
noun
a haploid spore, usually larger than a microspore of the same plant, which gives rise to afemale gametophyte: found in all vascular plants that have differentiated sexes in the gametophyte