CityGen3D is packaged with a selection of trees that can be added to your scene. You can also customise your scene with your own tree models.
Adding trees to your terrains in CityGen3D is really easy. Tree types mapped in OpenStreetMap can be linked to 3D models so that individually mapped trees can appear on your terrains.
Distributing trees randomly across different surface types is also possible, allowing you to fill your forests and jungles with appropriate foliage.
Any changes to your tree distribution rules can be easily applied to you selected terrains.