Click on the text link under each photo to see a larger picture.

Conks - fruiting bodies - at base of infected tree
Photo credit: Minnesota Department of Natural Resources Archive
Minnesota Department of Natural Resources
Bugwood.org

Popcorn conk of Heterobasidion annosum with penny for size comparison
Photo credit: Joseph O'Brien
USDA Forest Service
Bugwood.org

An irregular pattern of staining in root and butt heartwood is a sign of infection.
Photo credit: John W. Schwandt
USDA Forest Service
Bugwood.org

Borax treatment on freshly cut stump
Photo credit: Robert L. Anderson
USDA Forest Service
Bugwood.org