Are the trees small and green?
No, the trees are green but large.
    src        edge_attr  dst
0     0   to the left of    9
1     3   to the left of    6
2     4  to the right of    8
3     4  to the right of    6
4     4  to the right of    5
5     5   to the left of    4
6     6  to the right of    3
7     6   to the left of    4
8     8   to the left of    4
9     9  to the right of    0
10   11               on    7