Rock Elm (Ulmus thomasii)

Form

Height 80 to 100 feet, diameter 2 to 4 feet; seldom forks like other elms, but retains a straight central trunk; forming a narrow, rounded crown with long, graceful branches.

Bark

About 1 inch thick, ash-gray; divided by deep, irregular fissures into broad, flat ridges; corky ridges or wings develop on the bark of the twigs.

Leaf

Alternate; double-toothed margin; resembles those of the American elm, but are more regular in shape, smaller, smoother on both sides, and more leathery.

Fruit

A samara, length 1/2 inch, ovate, flattened; contains one seed; slightly notched at outer end; ripens in early summer.

Range

The rock elm reaches its best development in Wisconsin on the well-drained soils of Langlade and Shawano counties, but it is found southward and westward throughout the state on a variety of soils.

Wood

Close-grained, compact and strong; light reddish-brown with thick, light-colored sapwood; used for agriculture implements, sills, ties, hockey sticks and furniture.

Notes

Susceptible to Dutch Elm disease.