Vivid colors and nice composition. However, the focus seems a bit off only around the edges. I would have voted higher if the whole plant was in sharp focus.
I't looks to me that you have painted the background with black color in photoshop or some software. Not very well done ... if I'm wrong then ... hehe don't know what it could be then :P
Beautiful colors and nice job with the all black background! I think I might have liked it cropped a little more, eliminating a little off the right and the top... but thats just me. I like your dof. Good luck.