Mycelial fans of Armillaria ostoyae, cause of Armillaria root disease, under the bark of a dying sugar pine.
Photo by: Ellen Michaels Goheen or Donald J. Goheen Date: c.2012
Credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Southwest Oregon Forest Insect and Disease Service Center Source: Goheen, E.M. and Goheen, D.J., 2014. Status of sugar and western white pines on federal forest lands in southwest Oregon: Inventory query and natural stand survey results. Pacific Northwest Region. SWOFIDSC-14-01. www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5447311.pdf