not sure if your sensor is dirty or not (left side) or if those are just sun reflections/spots...IMO this needs a stronger application of a noise filter
i really like the silhouette of the inside part of the flower!
the one problem i see with this photo is that one of the petals is slightly out of focus. i would suggest a larger numbered aperture to increase your depth of field.
This is one of the few pix. in the challenge that actually delivers in black and white. The back lit emphasis really works to hold interest....especially concentrating on the edges, overlaps and the xylem and phloem tubes...the choice to NOT concentrate on the pistils and stamen, to take the angle from the opposite side further enhances the subtle nuances you have chosen to concentrate on and I am captivated! Where do you live? Is it summer there already?!!!!