Problem with Material Properties

Hi there,

I am trying to set material properties of different objects. So far, i have been able to change properties of terrain, dts objects and diffs. The problem now is that i want to do the same with "Tree" objects and what i have learned so far is that tree "leaves" (the green part) is'nt a TSShape. Does anyone has any idea how the desired functionality could be achieved or what exaclty are the tree "leaves"?

Any help in this regard will be apprecitated.