Botanical name: 

"Slippery elm," Ulmus fulva, is a middle-sized tree found abundantly in the natural woodlands of the Central and Eastern United States, from Canada to the South. The Indians and settlers of North America valued the inner bark of this tree as a poultice; in certain skin diseases they used it as an external application, and as a soothing drink in fevers. In bowel affections they employed a cold decoction. Schopf (582), 1787, refers to it as "salve bark." An infusion made by digesting the shredded inner bark of slippery elm in cold water, has (after the teaching of the Indians) ever maintained a high reputation in domestic North American medication in fevers, and especially in diarrheas connected therewith. The mucilaginous qualities render the powdered bark peculiarly adapted to the making of poultices, in which direction it was known to all the early settlers of America and was by them introduced to the medical profession.

The History of the Vegetable Drugs of the U.S.P., 1911, was written by John Uri Lloyd.