White rings on trunk of maple tree.
As near as I can tell, this looks like lichen. Lichens are not harmful to your tree, they are just using it as a foundation to grow on. They grow in many different designs, and yours look like rings. If you 'google' lichens and click on images, you will many different forms. The following sites are very informative. http://msue.anr.msu.edu/news/what_are_lichens_and_what_are_they_doing_on_my_tree http://msue.anr.msu.edu/news/liking_lichens_in_the_landscape I hope this was helpful. Feel free to contact us again if you have further questions.
Thank you for giving us a response that we dreamed of . It's a good ole tree.
I have checked with our resident "expert" and this is what she sent me:
"It is a fungus that parasitizes lichens on trees, completely harmless. We had the diagnosis from Jan Byrne at MSU CIPS Diagnostic lab, who had reached a lichen specialist in the MSU Herbarium at the time, Alan Fryday. The fungus is called Althelia arachnoidea, and it is a common lichen parasite, especially in polluted areas."
We had a case of this 10 years ago when I worked the hotline at the extension. I remembered seeing it but could not remember what it was called. This clears it us for both of us! It makes a nice conversational piece.
Have a good summer.