Developing a grand and majestic vase-like shape, the American Elm is a native riparian species that was formerly widely planted as a street tree (in New Haven as early as the 1690s) and is the namesake of New Haven’s familiar epithet, “The Elm City.” Dutch Elm Disease, a fungal affliction of Asian origin spread by bark beetles has killed most of the American Elms in New Haven and other cities since the 1950s, and much research has been devoted to breeding American Elm strains that are resistant to the disease.