A brown sunken canker with sharply defined borders with healthy green tissue. A Phomopsis canker, Phomopsis sp., with many black, tiny fungal fruiting bodies (pycnidia) that have erupted from the diseased bark.

A brown sunken canker with sharply defined borders with healthy green tissue. Many black, tiny fungal fruiting bodies (pycnidia) have erupted from the diseased bark. Credit: Theodor D. Leininger, USDA Forest Service, Bugwood.org<br />Licensed under a <a href="https://creativecommons.org/licenses/by/3.0/us/">Creative Commons Attribution 3.0 License</a>
Credit: Theodor D. Leininger, USDA Forest Service, Bugwood.org
Licensed under a Creative Commons Attribution 3.0 License