Conks are fungi that grow on trees. Like mushrooms, what you see are just the fruiting body of the fungus, most of the fungus grows unseen under the ground, or in the case of conks, inside the tree. Fungi doesn’t have chlorophyl and so it can’t make sugars from sunlight to feed itself, it must live off of the nutrients that they find within the tree. They deteriorate the tree and cause rot. If you see a conk on a tree you know that inside the fungus is growing and rotting the tree.
The bark of the tree is like our skin. One of its main functions is to keep all the bad stuff out of the body. Once the skin (or bark) is broken or cracked, organisms can get in and cause infections.
The photo shows part of a birch tree that had fallen and was lying across our trail. When I cut it up to get it off the trail, the fungus had easy access to the inside of the tree, and it looks like it found a lot of what it needed to grow because it six conks to spread its spores around hoping to find other vulnerable trees.
My paintings can be seen at: www.davidmarchant.ca