What is growing on the rocks that look dark brown?
The grass is growing on the rocks.
    src        edge_attr  dst
0     0   to the left of   11
1     0   to the left of    8
2     1   to the left of   12
3     1   to the left of    2
4     2  to the right of    1
5     4  to the right of   11
6     5  to the right of    9
7     6               in    7
8     6   to the left of    9
9     6   to the left of    8
10    8  to the right of    9
11    8  to the right of   13
12    8               in    7
13    8  to the right of    0
14    8               in    3
15    8    walking along    0
16    8  to the right of    6
17    9   to the left of    8
18    9   to the left of   11
19    9  to the right of   16
20    9  to the right of   15
21    9   to the left of    5
22    9  to the right of    6
23   10       growing on   13
24   11  to the right of    0
25   11   to the left of    4
26   11  to the right of    9
27   12  to the right of    1
28   13   to the left of    8
29   15   to the left of    9
30   16   to the left of    9