Meaning of

In gymnosperms multicellular female gametophyte retained on parent sporophyte

Most of the pteridophytes produce similar kinds of spores hence called homosporous.

Genera like Selaginella and Salvinia which produce two kind of spores, macro (large) and small (micro) spores are known as heterosporous.  Microspore and macrospore germinate and gives rise to male and female gametophyte respectively.

The female gametophytes in these plants are retained on the parent sporophyte for variable period.  The development of zygote into young embryo takes place within the female gametophytes.

Most of the pteridophytes produce similar kinds of spores hence called homosporous.

Genera like Selaginella and Salvinia which produce two kind of spores, macro (large) and small (micro) spores are known as heterosporous.  Microspore and macrospore germinate and gives rise to male and female gametophyte respectively.