Many foods are associated with certain cuisines and I understand that is the case with collards and the southern US states. However that doesn't have to mean that is where they originated.
It is hard to imagine Italian food without tomatoes, for example, yet they certainly didn't originate there. Closer to (my) home, Sichuan food without chillies peppers? Impossible, yet they too are from far away and only introduced relatively recently.
Ireland and potatoes?