Ulmus rubra Muhl. - syn.Ulmus fulva Michx.- Ulmaceae - slippery elm, red elm, Rot-Ulme

Deciduous tree, native to central and eastern North America; bark brown to red; buds obtuse, scales red, margins red-tomentose; leaves obovate to ovate, pubescent, serrate; flowers green to reddish; samaras yellow to cream, suborbiculate, broadly winged.
„The red-rust, mucilaginous inner bark of Ulmus rubra is distinctive; its sticky slime gives this tree its common name of slippery elm. Native American tribes used Ulmus rubra for a wide variety of medicinal purposes, including inducing labor, soothing stomach and bowels, treating dysentary, coughs, colds, and catarrhs, dressing burns and sores, and as a laxative.“
http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501329

The powdered (inner) bark of the slippery elm tree has long been used by Native Americans to treat cough, diarrhea, and other gastrointestinal complaints. It has been studied for use as a supplement for inflammatory bowel disease.
[Herbal medicine in the treatment of ulcerative colitis., Ke, F., Yadav, P.K., Ju, L.Z., Saudi journal of gastroenterology: official journal of the Saudi Gastroenterology Association, Vol.18(1), 2012, 3]
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3271691/

Sargent, C.S., The Silva of North America, vol.7: t.314 (1898) [C.E. Faxon]
http://plantgenera.org/species.php?id_species=1041994