One of my favorite stories is from when I was testing different cultivars of brassica for inclusion in the BioLogic mixes. My neighbor at the time, as country as he could be, came to me and said he hoped I didn't mind that he had been making salads from the "turnip greens" I was growing. When I told him those weren't turnip greens but actually experimental plants from New Zealand, he turned green and just about threw up!
But actually they are edible (since brassicas are all in the turnip family).