is or was part of
whole plant
plant structure
portion of a plant
A PO:'plant structure' (PO:0009011) that is not a whole organism; i.e. a proper part of a PO:'whole plant' (PO:0000003). Note that a 'portion of a plant' need no longer be physically part of the 'whole plant' from which it originated (e.g., a herbarium specimen).