Chestnut rescue -- 001

Chestnut rescue -- 001

Chestnut leaves

The chestnut blight, accidentally introduced to North America sometime after 1904 when Chryphonectria parasitica was brought into the United States on Japanese nursery stock, killed billions of trees. It is estimated that in some places, such as the Appalachian Mountains, one in every four hardwoods was an American chestnut.

Image: Michael Houtz / Penn State