A primitive form of the broccoli plant that isn't very tasty. I'm told that the broccoli we get at the store in the USA is a genetic mutation of the raab plant. Note that some people spell it rabe.

DJ Barbie Smooth from The Sound of Urchin used to get the crowd chanting, "Oh-my-god-broc-ali-raab" during TSOU concerts. It led to a t-shirt with the saying on it. It's sold out now.