Slippery elm, Ulmus rubra, outer bark used to make the salve.  Outer bark used to induce abortions. Inner bark dried and powdered added to water for gastric ulcers, duodenal ulcers, colitis.

(More information)

Description:  leaves 3-5 inches, alternate, deciduous, ovate, usually broadest at middle, taper abruptly to a point with a double row of coarse teeth, softly hairy underneath and smooth to rough on top.  Fruits of late spring are notched at the end.