Ornamental Cherry Tree

[landm42006]

Hello all. I live in NC where this summer has been very long, very hot and very humid. The other day I was watering all of my trees and noticed my ornamental cheery tree has this powdery rust looking cuts all over the trunk and limbs. I touched them and it was like touching a butterfly, the powder transfered to my fingers. I've looked online to what this could be and there's so many things, so I thought who better to ask them my fellow gardeners at the helpful Gardener. I hope someone can answer my question, and if needed I can supply a picture. I hope it's something that's treatable because it's one of my favorite trees in the spring. Thanks everyone.