A heterosporous life history occurs in some pteridophytes and in all seed plants. It is characterised by morphologically dissimilar spores produced from two types of sporangia: microspores, or male spores, and megaspores (macrospores), or female spores. Some genera of division Pteridophyta like Selaginella and Salvinia produce two kinds of spores, macro (large) and micro (small) spores, which are known as heterosporous.