Step 1: Just behind a shoot or root apex, three primary meristematic tissues appear, each named for the mature tissue it produces: protoderm forms epidermis, procambium forms primary vascular tissue, and ground meristem forms cortex and pith.
Step 2: Rib meristem instead refers to a pattern of cell division, where cells divide by walls at right angles to the long axis producing longitudinal files, seen for example in pith or root cortex formation. It describes a mode of division, not one of Jackson's three primary meristem types.
Step 3: Therefore Rib meristem is the option that does not belong among Jackson's three types.