Posted 10/8/2015 4:26 PM (GMT -6)
According to a Modern Herbal http://www.botanical.com/botanical/mgmh/e/elmsli09.html slippery elm bark "has an odour like Fenugreek and a very mucilaginous, insipid taste.....The powder should be greyish or fawncoloured. If dark or reddish, good results will not be obtained. The powdered bark is said to be often adulterated with damaged flour and other starchy substances."
Goes on to list many uses, including recipes for diarrhea, worms, and many other ailments. I used to own a 2-volume set of A Modern Herbal, it is a highly regarded botanical dictionary.