There are many ways to light a fire and some of the basic deliver the most satisfaction. So have you ever tried to light a fire from a simple spark using a piece of flint and a steel? This should not be confused with a firesteel, one of those ferro or ferrocerium rods. When a firesteel is scraped properly it provides a shower of bright, white and extremely hot sparks to ignite a tinder bundle. Chipping away at a piece of flint with a steel by contrast creates paler sparks that are a cooler orange and far more sensitive to the tinder used.
Why do I need char cloth? To ignite a fire with a dull or pale spark, you will need a very dry tinder. With a very hot spark (e.g. firesteel), you may be able to light tinder that is damp, all be it not obviously so. With a piece of flint struck with a steel, the tinder will not ignite if the tinder is even slightly damp. This is why you need a very dry tinder called char cloth.
Foraging has a way of connecting us with nature, in that it requires the forager to learn to observe their environment in an intimate way. It also has an aspect of connecting us to the past, back to our hunter-gatherer ancestors who foraged as a way of life. The tinder polypore, also known as the Iceman Conk, was one of a few wild mushrooms found on the body of a nomad found in the Swiss Alps and dated back to 3300 BC.
The other mushroom he was carrying was birch polypore (fomitopsis betulina), and pieces of it were strung on a necklace. That is also a type of tinder mushroom, but since it was found far from his tools on a necklace, researchers assume he was using that mushroom to treat intestinal parasites.