anther wall secondary parietal cell layer anther wall outer secondary parietal cell layer PO:0006009 PO_GIT:359 葯壁外二次側膜細胞層、壁細胞層 (Japanese, exact) In many angiosperms, including <i>Arabidopsis</i>, it differentiates into the anther wall endothecium. Alternatively, it may divide periclinally to form an anther wall endothecium externally and an anther wall middle layer internally. pollen sac outer secondary parietal cell layer (exact) plant_anatomy capa externa secundaria de c&#233lulas parietales (Spanish, exact) An anther wall secondary parietal cell layer (PO:0006007) formed towards the outside, after an anther wall primary parietal cell layer (An anther wall secondary parietal cell layer (PO:0006006) undergoes a periclinal division.