Lovely colour choice. I'd like to see this with maybe a 5x4 crop and the flower rotated a little more a'clockwise. Also the reflection seems very grainy compared to the image. I agree with Johnna TCGuru that a touch more light on the subject might really make this pop.
I really like the yellow and black. Good colour choices. I'd like to see you do this one again with just a burst of a small light on one part of the flower. Kind of a low-key thing. :)