What is "megaspore"

1857, from mega- + spore.

n. (context botany English) The larger spore of a heterosporous plant, typically producing a female gametophyte

n. larger of the two types of spore produced in heterosporous plants; develops in ovule into a female gametophyte [syn: macrospore]

Megaspores, also called macrospores, are a type of spore that is present in heterosporous plants. These plants have two spore types, megaspores and microspores. Generally speaking, the megaspore, or large spore, germinates into a female gametophyte, which produces egg cells. These are fertilized by sperm produced by the male gametophyte developing from the microspore. Heterosporous plants include the following:

• seed plants ( gymnosperms and flowering plants)
• water ferns ( Salviniales)
• spikemosses ( Selaginellaceae)