Yellow birch has more 'Sergeant's stripes' than white or gray birch. Lot's of it growing in the Adirondacks. Do you ever start out from 'Adarondak Loj' at Heart Lake? Used to be one of my favorite jumping off points!
You can find the fungus growing on dead birches, and it really does look like a horse's hoof. But it really has to be treated with the chemicals and dried out well before it works as good tinder. (There is
NO SMELL once it's dried out!) You can't just use it 'as is' when you find it on a log. I was introduced to it when I started making fire pistons. Because the fungus would break off in small, pea-sized pieces, it was great for stuffing into the end of the plunger, and burned for a long time. I guess ancient man used to go to his local chemical supply store to purchase his potassium nitrate and uric acid, but I just piss on it...
Stitchawl