Very beautiful render! I fully agree with the crazy realism on the ground cover!
I also agree with Oshyan that something seems a bit off about the clouds. To me it almost looks as if (especially towards the right edge of the image) you can see the clouds following the curvature of the planet. That definitely happens in real life, but I think you'd have to be much higher in altitude than the ground cover suggests to see that. I could just be crazy though, that's always an option!
Seriously though, beautiful render!