leaf development stage vascular leaf development stage In some plants, the leaf developmental stages may occur in the same leaf simultaneously. For example, leaves maize (or other grasses) have various zones where stages are occurring along the length of the lamina. plant_structure_development_stage 2013-09-06T09:57:58Z PO:0025570 PO_GIT:555 A leaf development stage (PO:0001050) that occurs during the interval between the onset of the vascular leaf initiation stage (PO:0001051) and the termination of the vascular leaf senescent stage (PO:0001054). brianatkinson