gametophore

The gametophore is a developmental stage in the life cycle of bryophytes, which include mosses, liverworts, and hornworts. It develops from the protonema, a filamentous structure that grows from a spore. The gametophore is the part of the plant that produces the sex organs, making it crucial for sexual reproduction.1

In mosses, the gametophore typically appears as an erect, leafy shoot, anchored by rhizoids. These leaflike structures, called phyllids, are arranged spirally around a stemlike axis. In liverworts and hornworts, the gametophore can be more flattened or thallose (undifferentiated). The gametophore is the dominant, photosynthetic generation in the bryophyte life cycle.12