No, it does not mention that in the market. I have just put this same combo in my normal breeding cave. I have watched my metal and willow frolic together for 3 minutes, and there is still no breeding bar above their heads, so I don't know what I have yet...must be a glitch, as that has never happened to me before....just gone back in and still nothing - weird. Edit - just went back in agin and it's a pollen.
I have finally reached the max of level 35. I have 6 more dragons to get before all gold. 3 plant/metal 3 air/metal will level up my last 3 shrines - yay, so close I can smell it. 3 malachite and 3 chrome, just need to get my malachite first...But NO ruby in sight.