I've been reading on Wikipedia about how plants alternate generations between a diploid sporophyte (usually the dominant part) and haploid gametophyte (in flowering plants, the pollen and ovule sacs).
Mammals also produce haploid gametes. But in mammals we don't describe the gametes as a separate generation that alternates with the dominant "sporoid." The gametes are just the organism's means of reproduction.
What is it about plant reproduction that warrants describing their gametes as a separate "generation" or "phase"?