Chestnut blight
![](/Images/godic/202501/04/Chestnut_blight4454.jpg")
![A chestnut tree that has been cut down, with blight on its inner bark and trunk](/Images/godic/202501/04/Chestnut_blight_on_cut_tree_in_Adams_County_Ohio4454.jpg")
The pathogenic fungus Cryphonectria parasitica (formerly Endothia parasitica) is a member of the Ascomycota (sac fungi) taxon, and is the main cause of chestnut blight—a devastating disease of the American chestnut tree that in the early 1900s caused a rapid, widespread die-off of this once plentiful tree from its historic range in the eastern United States.