I am remembering when my Dad was up here and pointed the plant out, again down near the barn, and after seeing this article I am thinking the poultice was from plantain. He said she use it for a poultice.
https://commonsensehome.com/grandma-called-it-medicine-leaf/
Dang I thought I was on an elderberry trail but here is onfo on a plaintain poultice. Could come in very handy.
https://keeperofthehome.org/make-use-plantain-poultice/
Someone stop me. I need to get some things done. LOL