King Alfreds Cakes

I've commonly found King Alfred's Cakes on Elder and Ash, they range in size from 2 or 3 cm to hand sized, black or dark brown in colour and hard to the touch.  When dry if you break one open and the interior reminds you of charcoal and easily takes a spark from a fire steel; you can scrape some into your tinder ball too for ease of combustion.  Once lit you can transfer the ember to a tinder ball for fire starting or you can carry the ember for fire starting later.  A resource worthwhile  collecting if you come across them.