Linked from
The 13 pages that link to Heterospory, each with the reason it gives.
GametophyteRelated: It separates gametophyte sexes by the kinds of spores from which they develop.
StrobilusRelated: Some strobili bear distinct sporangia producing microspores and megaspores.
IsoetesRelated: Isoetes produces both spore sizes, in separate sporangia at leaf bases.
SelaginellaRelated: Most Selaginella species produce separate microspores and megaspores.
LycopodiopsidaRelated: Quillworts and Selaginella produce separate microspores and megaspores.
SalvinialesRelated: Living water ferns produce separate male and female spores, unlike most ferns.