Hello!

I need an low poly 3d tree for my engine but i cant find any free ones. Can you please help me? I searched for about 3 hours until now..

http://www.turbosquid.com/Search/Index.cfm?keyword=trees&x=0&y=0

Turbosquid is pretty good for stuff like that.

This might be a bit more complicated than you were after, but Tree[d] might be worth looking at. It procedurally builds the trees from customisable parameters.