part of part of plant structure multi-tissue plant structure cardinal part of multi-tissue plant structure Includes cardinal parts of plant organs (PO:0025001) as well as parts of other multi-tissue plant structures. Cardinal refers to the fact that these are biologically meaningful and not arbitrary parts. Most cardinal parts of multi-tissue plant structures have both fiat and bona-fide boundaries, including parts with large fiat boundaries, such as leaf base (PO:0020040) or fruit distal end (PO:0008001), and parts with primarily bona-fide boundaries, such as leaflet (PO:0020049).