Hi, I'm new to the forum here, and I was wondering if anyone could help me identify what is growing on the underside of my maple tree's leaves. I've never seen anything like this, and I have searched in vain for an identification. The closest thing I could find was just a powdery mildew, but that doesn't really look like this, since no pictures of powdery mildew I could find had hairs all over it. Also, I don't know if it was the slight breeze, but I could have sworn these hairs were moving on their own, like they're some sort of parasite. Any help would be greatly appreciated. I've attached a picture of what I'm talking about. Thanks in advance!