Native to Canada, the rock elm occurs in southern Ontario and Quebec, as well as in the north-eastern United States. The rock elm can grow up to 25 metres high and live to 175 years old.
The leaves are asymmetrical, in other words, their shape varies along the central vein. They turn bright yellow in autumn.
The fruit is a round key, wing-pointed at the tips and covered in a fine hair.
The rock elm grows best on clay and chalky soils, but can adapt to a variety of soils. It is moderately shade-tolerant.
It has the hardest and heaviest wood of the elms. For that reason, it was once used for making musical instruments, chairs, railway track sleepers and even hockey sticks. Today, the species is much too rare for commercial use.
Leaves, alternate, simple, teeth incurved, somewhat hairy.
Fruits, rounded, hairy key, pointed at tip.