Ulmus thomasii, the rock elm or cork elm, is a deciduous tree native primarily to the Midwestern United States. The tree ranges from southern Ontario and Quebec, south to Tennessee, west to northeastern Kansas, and north to Minnesota.
The tree was named in 1902 for David Thomas, an American civil engineer who had first named and described the tree in 1831 as Ulmus racemosa.
Ulmus thomasii grows as a tree from 15–30 m (50–100 ft) tall, and may live for up to 300 years. Where forest-grown, the crown ...