test
node1
PO:0000146
abscission zone
node2
PO:0006211
separation layer
node1->node2
node3
BFO:0000040
material entity
node4
PO:0025131
plant anatomical
entity
node3->node4
node9
PO:0009011
plant structure
node4->node9
node5
BFO:0000001
entity
node6
BFO:0000002
continuant
node5->node6
node6->node6
node7
BFO:0000004
independent
continuant
node6->node7
node7->node7
node7->node3
node8
PO:0009007
portion of plant
tissue
node8->node1
node8->node2
node9->node8