When two plant gamete
s fuse to form a diploid zygote
, that zygote develops into a sporophyte. Sporophytes are diploid, and have reproductive tissues that undergo meiosis
to produce haploid spore
s. These spores develop into the gametophyte
generation. Gametophyte individuals produce gametes, starting the cycle over again.
In higher plants, which include the conifers and angiosperms, the sporophyte generation is the thing we recognize as "the plant." The gametophyte generation is reduced in size, with pollen grains representing the male gametophyte. The female gametophytes are contained within ovules inside flowers or cones, and remains parasitic on its diploid parent throughout its existence.