I like the translucency, but there is something about it that bugs me, and I don't know what it is...maybe the color of the background? Maybe thelittle extraneous "leg" (not the stem, the little tendril to the left of the stem). I wonder what it would have looked like if you had picked that off.
Nicely done - this was a good idea. I'm not so sure about gray as the background color. Creative though, and well composed. Good luck in the challenge.