1) Monogenesis 2) Sporulation 
Heterospory is the production of spores of two different sizes and sexes by the sporophytes of land plants. Heterospory was evolved from isospory independently by several plant groups in the Devonian period as part of the process of evolution of the timing of sex differentiation. Heterosporic plants produce small spores called microspores which ei...
(from the article `plant`) A heterosporous life history occurs in some pteridophytes and in all seed plants. It is characterized by morphologically dissimilar spores produced ... By the Middle Devonian Period (387 to 374 million years ago), the heterosporous life cycle had evolved independently in several groups, including ... ...The...
<plant biology> Condition in vascular plants where the spores are of two different sizes, the smaller producing male prothalli, the larger female prothalli. ... (18 Nov 1997) ... 
Condition in vascular plants where the spores are of two different sizes, the smaller producing male prothalli, the larger female prothalli.
[n] - the development of both microspores and megaspores
heterosporous, heterospory Producing two different kinds of spores.