perianth

The perianth in bryophyte anatomy refers to a protective sheath surrounding the female reproductive organ, the archegonium. This structure is found in some leafy liverworts and functions similarly to the paraphyses in mosses, offering protection to the developing archegonia.1

Bryophytes, which include mosses, hornworts, and liverworts, are nonvascular, seedless plants that exhibit an alternation of generations between a gametophyte and a sporophyte. The gametophyte is the dominant, independent generation, producing the sex organs. The sporophyte, which develops from the fertilized egg within the archegonium, is typically dependent on the gametophyte for nourishment. Bryophytes lack true roots, stems, and leaves, and their reproductive structures are generally simple.234