Spruce trunk with reddish decay caused by Heterobasidion root disease, <i>Heterobasidion annosum</i>.
Spruce trunk with reddish decay caused by Heterobasidion root disease, Heterobasidion annosum.
Credit: Andrej Kunca, National Forest Centre - Slovakia, Bugwood.org
Licensed under a Creative Commons Attribution-Noncommercial 3.0 License