The next in the series of ongoing free tree models are 5 Japanese Maples (Acer Palmatum). The textures included are diffuse & displacement for the bark and 3 diffuse variations of the leaves.
I went for the more red / purple colour on the leaves for this set of trees, but of course with some adjustment in Photoshop you could derive a greener looking version. As I'm progressing in getting to know GrowFX better and better, the models increase in detail and finish. The leaves of this set have the right orientation to be used with double-sided materials, after I (finally) tackled a little bit of an issue I was having with flipped leaves.
If you're a GrowFX (potential) user, I highly recommend dropping by their forum. The community is an incredibly helpful bunch, quick to help you solve any trouble you might be having.