Make the second tree NORMAL instead of EVERGREEN.  Turn on alpha blending when rendering the scene, so foliage textures (with alpha) work closer to right.  (Unfortunately this means I now need to sort polygons before sending them to the video card... which means the prebuilt buffer is useless, because it depends on the camera position/angle.  That might destroy the whole plan here.  :-/  We'll see.)  Return to the normal bark texture.  Use the right limits when generating leaf objects, in both for loops (one was off by one, the other was half of what it should have been).  Force the alpha to 1 when generating each leaf's color.  Fix the render-to-texture issues by using TRIANGLES instead of TRIANGLE_FAN, because the leaf texture is drawn with multiple quads, not just one.  Fix up the rotation matrix as well (do the proper translations before and after the rotation).  Enable blending while drawing the tree textures, because each leaf's alpha needs to show through the leaf below it.