Some Things I Think ... I Think ...

There is a rough black growth on the side of a scaly yellow birch. Chaga. True Tinder Fungus. It is used to make a coffee-like beverage. Medicinally it has a variety of uses including that of a cancer remedy. It is also an excellent source of tinder for fire-making.

Chaga Tinder Fungus is one of the best natural tinder's available and one of the few that can be used without charring. Chaga is the common name for a tinder fungus that can be found growing on injured areas of the white birch tree. Not only is it a premium tinder for use in Fire Pistons and with spark-based fires (including Pyrite on Pyrite), Chaga can also be made into a delicious caffeine-free coffee substitute beverage.

http://www.survivalschool.com/products/fire_starting/Tinder_Fungus.htm