develops_from develops from xylem primary xylem A portion of xylem (PO:0005352) tissue that develops from the procambium (PO:0025275). plant_anatomy xilema primario (Spanish, exact) 一次木部 (Japanese, exact) PO_GIT:434 PO:0005849 Primary xylem develops as part of primary growth (request for primary growth has been made to GO) and is not differentiated into axial (PO:0025410) and ray (PO:0025411) systems. Tracheary elements (PO:0000290) have lignified cell walls with secondary thickening and are dead at maturity. portion of primary xylem tissue (exact) procambium anatomical entity