The American Chestnut and Blight

May 2, 2005

The American Chestnut ranged from Maine to Georgia and west to the Mississippi River.  First discovered in 1904 in the Bronx Zoological Park, New York,within 50 years the blight had spread throughout the American chestnut’s entire range.  The blight is caused by the fungus Cryphonectria parasitica, introduced from Asia. It enters the tree through cracks typical of chestnut bark and through wounds.  The fungus forms a canker and quickly girdles the tree, destroying the inner bark layer and cutting off the tree’s water supply and nutrients. The part of the tree above the girdled area dies.  The American chestnut continues to sprout from roots and stumps with some shoots growing large enough to flower and fruit before the fungus attacks it. The American chestnut survives since the blight fungus cannot live in the soil and because the tree has a tremendous capacity to produce shoots from stumps and roots.