Mosses are classified as bryophyte plants. In bryophytes, the gametophyte phase is the dominant stage of the life cycle, unlike vascular plants (pteridophytes, gymnosperms and angiosperms). Gametophyte in bryophytes is independent of sporophyte and also more complex. In the other plant groups, in turn, the gametophyte is less complex and usually nutritionally dependent on the sporophyte.
I'm guessing sporophyte. I know mosses are nonvascular (they don't conduct their own food or water). They go through haploid and diploid phases. The haploid phase is most prominent in mosses. Sorry if this isn't helpful.
