Uny, Willow, Mac&Cheese; Is black walnut and walnut interchangeable?

Uny, Willow, and Mac&Cheese(sp), About a month ago I was asking where I could find walnut leaves or walnut bark. All of you answered as if Black-Walnut and walnut were one and the same. Can any of you tell me if that is indeed correct? I can't seem to find the information by searching. I don't want to switch ingredients from the original recipe given by Dr Christopher unless one of you know that it is perfectly ok to do that.

Can I find that out from any of you.

Thank you.

nb