The United States is home to several species of ash, including the commercially viable Fraxinus americana (white ash), Fraxinus pennsylvanica (green ash), Fraxinus nigra (brown and black ash ...

Much work remains to be done, according to Rutledge. Green ash (Fraxinus pennsylvanica) and black ash trees (Fraxinus nigra), for example, do not seem to possess the resistance of their white ash ...