enlarge your 3ds import file,rotate it flat, export as an obj, open in uv mapper, assign the leaf to a new material, planar map the leaf to its own template, save the object. Then make a large bitmap image (like 2000 x 2000 or so) and either take a picture of a real leaf or find one on the internet. Paste the leaf into your template, shrink the file down to about 700 x 700, save, and apply it as a texture to your leaves. Take the same picture, desaturate it, increase the contrast, and use it as your bump. You can just use simple object color for your stems, just apply a bump map with a lot of noise for texture. If your bump map is god, you shouldnt need a tremendous amount of detail.