portion of plant tissue amphithecium 2011-05-17T10:28:55Z 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 PO_GIT:364 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. anfitecio (Spanish, exact) plant_anatomy rwalls アンフィテシウム細胞 (Japanese, exact)