Commercial tinder, petroleum jelly-covered cotton balls, and dryer lint are all great for starting a blaze–until you realize you left them at home. But lucky for forgetful hikers, the woods are full of natural firestarters. One of the best: chaga, aka tinder fungus. This chunky black mushroom ignites easily, smolders for hours, and emits a pleasant, woodsy smell. Here's how to use it.
Chaga fungus grows year-round in cool northern forests from New England to the Northwoods of Minnesota and Wisconsin and into the southern Appalachians. Look for it on birch trunks; the dark, bulging mushroom resembles burnt charcoal and often sprouts up where the tree has been injured (chaga is a parasite; you won't become an LNT outlaw by taking a small chunk). Pry a palm-size piece of the fungus off of the trunk with your multitool.
Flint Scrape any part of your fungus chunk with a knife to produce a pile of powder, then direct sparks directly onto the pile. You can also place the fungus on the ground, off the edge of your flint or fire striker, and let the sparks land right on it. The highly flammable chaga will ignite no matter which method you choose.
Lighter Simply hold the entire chunk to a flame.
Adapted from Born to Explore: How to Be a Backyard Adventurer, by Richard Wiese ($19, HarperCollins)