Can Tree with terrain system be set up random rotation?

When using terrain in Unity3d, I arranged tree on the terrain by Tree brush and found all trees had same the rotation on the Y axis. It’s not very natural. Have the unity3d some options to set the random rotation for tree brush? So far I can found only random size.

I’m sorry, i also wanted to use that on my game, but because of the billboard, it’s not possible. I think that maybe if you made tree groups or many different trees, you can avoid that unnatural feel. But, sadly, unity doesn’t support random rotation. But hopefully, they’ll add this feature someday.