The Slippery Elm (Ulmus rubra) is a deciduous tree native to North America, recognized for its inner bark. This reddish inner bark becomes mucilaginous when wet and has a long history of use. The tree is also called Red Elm or Gray Elm. Ulmus rubra is a medium-sized tree that can live for up to 200 years.
Native Geographic Range
Slippery Elm is indigenous to the eastern and central regions of North America. Its natural distribution stretches from southwestern Maine west to New York, reaching into southern Quebec and southern Ontario in Canada. The range continues across northern Michigan, central Minnesota, and eastern North Dakota.
The southern boundary extends to northwestern Florida and Georgia in the Southeast, and west through central Texas and central Nebraska. The tree is present across most of the eastern half of the United States. It is most abundant in the southern Lake States and the Midwest’s “cornbelt” region, found naturally in 41 states, demonstrating its adaptability.
Essential Habitat Requirements
Within its native range, the Slippery Elm flourishes in specific environmental conditions, growing best on rich, moist soils. It is found along streambanks, river terraces, and in wooded bottomlands where the soil is moist and well-drained. The tree also grows successfully on lower slopes and alluvial flood plains.
While it prefers moist conditions, Ulmus rubra is adaptable and can tolerate drier sites, particularly those with a calcareous or limestone origin. It handles partial shade but thrives best in full sun. It grows well in rich, fertile loams or clay loam soils, but does not typically grow at elevations above 1,800 feet.
Key Identification Features
The Slippery Elm is a moderately fast-growing tree that typically reaches 40 to 60 feet in height. The mature tree usually develops a vase-shaped or broad-rounded crown with ascending and spreading branches.
The bark is dark gray, rough in texture, and deeply furrowed on mature trunks. The reddish inner bark becomes notably slimy when chewed or cut. The leaves are large, measuring between 4 and 8 inches long, and are oblong. They have a rough, sandpaper-like surface on top and are hairy beneath, featuring an asymmetrical base and double-serrated edges. The prominent reddish-brown buds, covered in rust-colored hairs, are noticeable during the winter months.