Wheat looks like grass if you aren't familiar with it. ditto potato plants - only the roots are what you want, and as they're invisible, if you don't know what

Wheat looks like grass if you aren't familiar with it. ditto potato plants - only the roots are what you want, and as they're invisible, if you don't know what a potato plant looks like, you'll have no idea you're looking at food, as OP says. I could go on for a while, but you get the gist.