Knowledgebase
Satomi Dogwood tress bark issue #926844
Asked March 26, 2026, 4:42 PM EDT
Lapeer County Michigan
Expert Response
Thank you for contacting Ask Extension. What you have is called lichen. Lichen is a living organism that is both algae and fungi. It has a symbiotic relationship with the tree it is growing on. It will not harm the tree. It sometimes will grow on slow growing trees and trees that are in decline. I have included a few references for you to look at.
If we can be of further help, please let us know.
https://extension.umd.edu/resource/lichen-algae-and-moss-trees/
https://njaes.rutgers.edu/fs1205/
https://www.canr.msu.edu/news/liking_lichens_in_the_landscape