Is this fungus on cherry blossom tree?

I have noticed a some branches on cherry blossom have no leaves or blossom so was going to prune once blossom has Gone. Noticed this on some of the branches. The tree had great blossom this year so assume generally in good health.

 

That looks like lichen to me. Lichen doesn't kill trees, just uses them to grow on.

 

That’s great thank you