Slippery Elm – the Medicine Tree

Kendal’s arboretum has two Slippery Elms, Ulmus rubra.

Both are in one of the cottage courtyards near Parking Lot No. 3. They were probably planted in the early 1970s when Kendal was being built and are estimated to be about 50 years old. One of them, No. 55 on the South Loop of the Arboretum, is monitored by Fran Nimeck, its Adopt-a-Tree volunteer.

The slippery elm is a medium-sized deciduous tree native to North America, particularly the eastern and central United States and eastern Canada. It can grow 50-60 feet in height, with a trunk measuring up to four feet in diameter; the largest one in Pennsylvania is nearly 100 feet tall. It is a rare or threatened species in some parts of the U.S., related to the American Elm that has been decimated by Dutch Elm disease, a deadly fungus (see below). A stately row of these elms used to border a walkway inside Longwood Gardens; only one remains.

Slippery elms have very small inconspicuous flower clusters in early spring, which develop into flat, round paper-thin fruits that are rather messy but rapidly decompose into the lawn. The alternate leaves have toothed margins and are dark-green, hairy, and abrasive on top, and a lighter green, hairy, and less abrasive on the underside.

The tree gets its common name from the mucilaginous inner bark that had many medicinal uses by Native American herbalists and early colonists. It was used as a burn treatment during the Civil War and was an important survival food for both the Native Americans and colonists during times of famine. The wood—dense, close grained, and very shock resistant—was often used for the hubs of wagon wheels. The yoke of the Liberty Bell was made from slippery elm, a signal honor!

Martin Wells and Judy Czeiner, Photographer


(From the Internet: A fungal disease of elm trees that is spread by elm bark beetles. A virulent strain of the fungus that arose in North America in the early 20th century has destroyed the majority of American elms in many areas.)