I like it from the first view. Negative space is a good choice. I like the fact, that you did not try to literaly change this flower into black. B&W was a good choice. Good contrast and clarity. Very delicate and elegant flower. Perfect symmetry underlined by your composition.
I was just reading about the Black Dahlia the other day. The tones in this really connect with the title. I like how you put the flower at the bottom left. Gives it a neat effect :o)