Love your composition, detail and DOF, Chris. My only suggestion would be to think about possibly cloning out the one stamen that is OOF against the back of the flower. The others are so well sharpened and detailed that I think the one kind of pulls the attention away from them a bit.
On the other hand, it's what makes the flower a flower and not some perfect version of a flower so I could really go either way. Now...if you follow the OOF stamen straight up the black BG you'll see a little fleck of green - that I would clone out just so you have a seamless BG. Great job on the white BTW.
Chris, It looks like velvet! I like the odd stamen.I like your crop. Agree w/ Julie about that small fleck of green- But that wouldn't stop me from hanging lg. print on my wall! Congrats!