portion of plant tissue amphithecium Term used for bryophytes. May have one or more layers. An amphithecium may give rise to an exothecium and other layers of a sporangium wall (jacket layer or layers). In true mosses, the amphithecium gives rise to the sporangium wall and the peristome. In hornworts and peat mosses, it gives rise to the sporangium wall and sporogenous tissue. A portion of plant tissue (PO:0009007) that is the outer layer or layers of a sporangium (PO:0025094) early in sporangium development (GO:0043582). PO:0030084 2011-05-17T10:28:55Z PO_GIT:364 rwalls アンフィテシウム細胞 (Japanese, exact) plant_anatomy anfitecio (Spanish, exact)