Three American tragedies: chestnut blight, butternut canker, and Dutch elm diseaseThis article is part of a larger document. View the larger document here.
Three North American tree species, American chestnut (Castanea dentata), butternut (Juglans cinerea), and American elm (Ulmus americana), have been devastated by exotic fungal diseases over the last century. American chestnut was eliminated from eastern forests as a dominant species by chestnut blight (Cryphonectria parasitica). Butternut is presently being extirpated, as butternut canker disease (Sirococcus clavigigenti-juglandacearum) spreads into northern populations. Urban and forest American elm populations have been decimated by Dutch elm disease (Ophiostoma ulmi and O. nova-ulmi). A combination of basic and applied research has been directed toward developing resistant trees of each species. Resistant American elms are now available for planting in urban settings. The prospects for reintroduction of resistant American chestnut, butternut, and American elm into eastern forests appear to be promising.