I grew-up (and still live in Tennessee). This was a Native American practice. As a child, we would frequently find a particular type of small bush in the woods, pull-part of the roots out of the ground, and wash it off. You would strip the outside sheeth (bark) off the roots, and then you would boil the sheeth and roots in water. The tea would be very sweet, and was "root beer." You could also just chew on the roots' bark. This was something we always did when we camped-out, I think that the tree was sasafrass,

Wilco in Tennessee