Ulmus
Valued for their fast growth, Ulmus are deciduous trees, with handsome oval leaves often coloring well in the fall. Some have superb exfoliating bark, which flakes to reveal patches of shades of gray, green, brown, and orange. However, elms are subject to a fatal disease, the Dutch Elm disease, which has killed millions of American elms throughout North America and can attack most other elm species. Considerable effort is being made to breed hybrids that are resistant to the Dutch elm disease.