I love that you kept this in black and white and the lighting is fabulous. I don't know if you intended a soft focus for artisitic sake, but in this case, a shaper image might have worked better. Particdularly at the bottom of the shot, it seems a little too out of focus, detracting from an otherwise perfect shot.
Wonderful shot...and meets the challenge. My sense is the lines of the large petal on the right distract from, ratyher than draw your attention to, the floral center. But I am not sure how to capture the shot to improve. nice work.