Tuscan kale, also known as lacinato kale, dinosaur kale or, simply, black kale. I love it deeply, as much as you can love cruciferous vegetables. Which, I've found, is actually quite a lot. It's one of those things I left behind in New York, along with a lot of other dark leafy greens, that seems impossible to find in Berlin. (Wherefore art thou, mustard greens?)
Trust me when I say I seriously contemplated ripping it out at the root.