Chestnut Blight Fungus (Cryphonectria parasitica)

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Phylum or Division: Ascomycota
Class: Pyrenomycetes
Order: Diaporthales
Family: Valsaceae
Identification: The fungus that attacks the American chestnut has the appearance of a large canker, and is typically found on the tree trunk or other tree surface area. It enters tree wounds and cracks and grows in and under the bark, killing the area around the tree twig, branch or trunk. Yellow or orange spores (called pycnidia) exude from the canker, and they are as small as a pinhead.

Project Editor: James A. Danoff-Burg, Columbia University