heterospory

The production of more than one type of spore by a species. Usually large *megaspores containing food   reserves   and   small   *microspores are formed. The megaspore eventually produces female gametes and the microspore male gametes. Heterospory is seen in certain lycopsids, e.g. Selaginella, in the water ferns, and in all the seed plants. The degree of heterospory is used as a diagnostic character in pteridophytes. Compare diplanetic.