test
node1
BFO:0000001
entity
node2
BFO:0000002
continuant
node1->node2
node2->node2
node5
BFO:0000004
independent
continuant
node2->node5
node3
PO:0009008
plant organ
node4
PO:0025004
plant axis
node3->node4
node15
PO:0004512
heartwood
node4->node15
node5->node5
node13
BFO:0000040
material entity
node5->node13
node6
PO:0009011
plant structure
node12
PO:0009007
portion of plant
tissue
node6->node12
node7
PO:0025496
multi-tissue plant
structure
node6->node7
node7->node3
node8
PO:0005352
xylem
node9
PO:0005848
secondary xylem
node8->node9
node9->node15
node10
PO:0009015
portion of vascular
tissue
node10->node8
node11
PO:0025409
secondary vascular
tissue
node10->node11
node11->node9
node12->node10
node14
PO:0025131
plant anatomical
entity
node13->node14
node14->node6