Male and female gametophytes do not have an independent free living...

Within the anther, there are special diploid cells called pollen mother cells or microspore mother cells. The microspore mother cells undergo meiosis to produce haploid microspores or pollen grains. Pollen grains represent the highly reduced haploid male gametophyte.

The function of carpels is to produce ovules or megasporangia. Within the ovules, there are specialized cells called the megaspore mother cells ($2n$). The megaspores mother cells are diploid ($2n$) which undergo meiosis or reduction division to form haploid megaspores ($n$). The megaspores produce a multicellular female gametophyte or embryo sac.