response: I actually don't know about that.  But even further back, in the 4th century BC, curly and flat leaved types of cabbage were known to already exist, in Greece.
original_response: it is but Curly-leaved varieties of cabbage already existed in that time
history: Kale is so good for you. I try to eat it every day. Nice!  I know that kale leaves don't make a head, like headed cabbages do.  Also, their leaves can be purple or green! Oh cool.  Do you know anything about the history of kale? Well, in Europe it was very common up until Middle Ages' end.  In fact, of the green vegetables, it was the most common! Wow! I guess it's a really hardy plant
knowledge: Curly-leaved varieties of cabbage already existed along with flat-leaved varieties in Greece in the fourth century BC.