So there are a few varieties of fungus that produce mushrooms which make excellent tinder.
In Europe the species best known for its ability to burn is Fomes fomentarius, but in North America we have Fomes excavatus. They look practically the same: horse hoof shaped conks attached to hardwoods which are perennial, developing new pore surfaces each growth season.
Here's a few images of Fomes excavatus being incinerated. This was shot on a Nikon D500 with a macro lens in front of a wood burning stove, so this almost singed my eyebrows lol.