What do both the tree and the field have in common?
The color, both the tree and the field are green.
   src        edge_attr  dst
0    0  to the right of    4
1    0  to the right of    3
2    2               in    8
3    3   to the left of    0
4    4   to the left of    0
5    6   to the left of   10
6   10  to the right of    6