American Chestnut
Castanea dentata
Four billion trees. One fungus. A nation that learned the word 'blight' the hard way.
By 1950, an accidentally imported Asian fungus, Cryphonectria parasitica, had killed nearly all of them. The remaining stumps still send up doomed shoots that die before they can flower. It is the largest ecological disaster in American history and almost nobody can name it.
