Mycelial fans of Armillaria mellea under the bark of an infected sweet chestnut tree.

Mycelial fans of Armillaria under the bark of infected trees.; Fremont, Alameda County, CA Credit: Igor Lacan, UCCE San Mateo and San Francisco Counties
Mycelial fans of Armillaria mellea under the bark of an infected sweet chestnut tree. Credit: Igor Lacan, UCCE San Mateo and San Francisco Counties