Slippery elm, or Ulmus rubra, is a tree native to the central and eastern United States and Ontario, Canada.
The tree is known for its dark brown to reddish-brown bark and can reach a height of 60-80 feet. Native Americans would peel its slimy, red inner bark from twigs and branches and use it as a remedy for many common ailments, like fevers, wounds, and sore throats.