In 1905, author Harriet Keeler wrote about the inner bark of the slippery elm tree: “It is thick, fragrant, mucilaginous, demulcent, and nutritious. The water in which the bark has been soaked is a grateful drink for one suffering from affections of the throat and lungs.”
Nutritious and medicinal, slippery elm is native to the eastern half of North America. At Valley Forge, George Washington's hungry troops survived on it for weeks; they also dressed wounds with it. Slippery elm is a gentle cure-all, soothing inflamed membranes of the throat, the digestive and urinary tracts and bowel. When eaten, it's easy to digest. But its modern popularity is also its downfall; for over a century, some people have harvested the inner bark of slippery elms by girdling the trees, which kills them. And since the 1930s, bark beetles carrying the Dutch elm disease fungus have attacked mature slippery elm trees, reducing the population in part of its range. But this is one medicinal plant that can be cultivated and harvested sustainably.