I've been looking at this one for a while now, and it has grown on me. I do like plant still-lifes anyhow, and have done quite a few in the past. It is a lot more difficult than you might think to do them well, so this one deserves a lot of praise, as others have said. The distribution of tone through the picture is well-handled, and the composition is very satisfying. I can easily imagine this framed and hanging on my wall.
As to the noise, well I'm not so sure. This looks like luminance noise to me, rather than colour noise, and I do not find it objectionable at the level we see it here - it looks awfully similar to film grain, and that never bothered me. I see it as a texture which becomes part of the image and in this context I would leave it alone.
John