My first inclination was to use hard light to emphasize the intricate detail of the leaf's veins. A snoot was chosen to turn my 300 WS monolight into a very small light source. Putting the light close gives some falloff, which creates the vignette effect (no photoshop for that). Sorry I didn't take a photo of the setup, but in the diagram above tells the story. Try to imagine the light above the camera with the snoot pointing down and its nose almost touching the lens hood. A white reflector at the right (my white balance disc) adds a little bit of fill.
That wraps this posting up. Haven't yet decided what to do next, but will think of something... and hopefully you will like it. :-)