Gald to be a part of what looks like a friendly place to chat all things gardening

I have a recent problem with my rowan and my privit hedge, they both seem to have the same fungus thing growing on them, it is a dry powdery grey fungus which is only on the bark and close up it looks like miniture coral if that helps....
What can I do about it ? my rowan and privit hedge suffered at the hands of the flood a couple of years ago if thats any info, also the rowan is very late coming into leaf now and the buds a very sparce.
Hope someone can help identify and cure this before its too late.
Kindest regards,
Ken.
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