If the grains were malted then kilned after gathering, and had sufficient enzymes to convert the starch into sugars in a mash, it could happen. Grains themselves without malting, doubtful. Which grains are you considering?
I would do a decoction mash if you're going to use wild grains. You'll need all the efficiency you can get. The only major difference will be that your efficiency will be a lot lower because the grains we use these days are basically designer grains.
I think. I'd definitely submit to another stance, but I'm pretty sure that's the gist of it.
Keg (serving): Belgian Pale Ale
Keg: Chocolate Cherry RIS