Foraging Fun: Fomes fomentarius

Fomes fomentarius, known by more readily decipherable names as tinder or hoof fungus, is a perennial polypore fungi that is indigenous to most regions of North America, Europe, North Africa and Asia. Despite it’s drab, mundane and seemingly uninteresting appearance that many of us have unknowingly passed by in the forests that we stroll through from time to time, this species possesses a rich ethnomycological significance to ancient societies that dwarfs that of some other more rambunctious fungi that we may commonly associate with today.

This species is a common sight in hardwood forests in my home region of southern Ontario, although like many individuals prior to being introduced to it sadly overlooked it’s presence in the landscape. From my personal observations and those of others that I have consulted prior to the publishing of this article, I have found the humble and unassuming tinder fungus to be quite fond of birch (Betula spp.) trees, particular white birch (B. papyrifera) which unsurprisingly is usually the most common and well-known species of that genus in North America. Where there are expansive stands of birch trees one could expect to find F. fomentarius among a wide assortment of other tree-dwelling fungi including a close relative of the tinder fungus, Piptoporus betulinus (another remarkable species which I ought to write about in extensive detail one of these days) which also prefers birch trees as a host.

A typical Fomes fomentarius growing from a fallen birch log. Individual mushrooms can survive for up to thirty years if not more, and each year a new layer is added to the base of the hoof-like fruiting bodies. New growth tends to be a clean white color and eventually fades to shades of gray and black.

An interesting habit of F. fomentarius is it’s curious ability to exist as a parasite of living birch trees, often infiltrating the living layer of tissue found just under the bark through broken branches or other open wounds and then continuing to live off of the wood itself after the tree has died. Usually this species, as well as other fungi that start off their lives as parasites, are unable to inflict healthy trees because they do not have a physical entry point in which to begin pirating the tree of it’s nutrients or are too easily fought off by the tree’s natural defense mechanisms, comparable to our own immune systems.

Inevitably though, trees are weakened by age, environmental degradation or wounds caused by other various natural forces and the spores of this fungus as well as others find their way into the tree and begin to overpower it’s defenses. Such a life cycle is profoundly important for nutrient cycling in a forest ecosystem, for without the ability for certain organisms to convert and recycle nutrients that have been used by the living into forms that can then be reassembled to create new and varied lives, the life of a forest would reach a climax state in which growth would slow down and eventually cease altogether. F. fomentarius, therefore, is a highly specialized and essential part of converting the dead back into usable elements that can be reconstituted to create new life or feed the ongoing nutritional hunger of the living.

This image displays evidence of the parasite-gone-decomposer tendencies of F. fomentarius. Since the pore surface of this species and many other macrofungi typically face the ground, it is evident that the largest polypore present grew when this particular tree was still standing and presumably alive ebefore it fell to the ground. After death, new fruiting bodies emerged later on and are facing the direction of the ground where it currently exists while the older polypore cannot change direction and but still appears to be growing.

An even older name for this fungus is amadou – a native European word that can be used to describe the species as a whole or a dense, fibrous material that can be made from boiling the young fruiting bodies (the part of the fungi that we most often see and identify as a ‘mushroom’) in water and then pounding them with stones until the dense, rope-like fibers which make up the polypore begin to separate. These twisted strands have a multitude of practical and medicinal uses that the majority of forest or non-forest goers have but almost entirely forgotten.

This material, when rubbed together to the point of tearing the individual fibers, is transformed into an unparalleled tinder. Indigenous people throughout the world that had access to amadou traditionally used it to both start and transport embers from previous fires long distances in order to relieve themselves from the trouble of having to restart a fire from scratch in a new area – that being a considerably difficult process using only natural materials that most of us are now incapable of performing. The fruiting bodies themselves were usually hollowed out with tools and embers were placed inside and would continue to smolder – sometimes for days – before being placed into fresh kindling and a new fire started when it was needed.

large amadou
An unusual specimen that like the photo above displays evidence of this fungi’s ability to switch from parasite to decomposer following the death (and subsequent falling over) of a host tree. New layers of tissue are added to each individual polypore every year as it grows and matures. The pore surface is composed of minute, congested tubes which house the spores.

Amadou was also used to fabricate clothes and other garments including hats*. The material was stretched out and the individual strands isolated and weaved into fibers that were thin and flexible enough to be woven into a type of cloth. Considering how dense the unmolested fruiting body of F. fomentarious is when observed in it’s natural context, it may be possible for one to grasp the outstanding durability of this material once it was processed, likely using nothing more than an overwhelming extent of brute force and good ol’ elbow grease.

Like many other polypore mushrooms that are closely related to F. fomentarius, including Phellinus igniarius, this fungus has recognized astringent and stypic properties and have been employed for such uses for thousands of years if not longer. Strap-like pieces torn from the inside of the fresh fruiting bodies or processed amadou were boiled in water, to hydrate it and increase it’s elasticity, and placed over wounds to absorb excess blood, treat inflammation and pain and help the wound to clot over and form a protective scab. This fungus was also taken internally in the form of a tea to treat inflammation, combat diarrhea, dysmenorrhea and bladder infections.

Remarkably, amadou was even believed to treat tuberculosis and cancers of the throat, stomach and uterus. However, these applications have not been demonstrated as plausible using modern scientifically recognized tests and analyses but these claims may none-the-less warrant further investigation by an experienced practitioner. Anyone who has studied the natural world for a length of time can contest to the fact that weirder things have happened than a rock-like fungus being used to treat cancer, and so by no means should we be so careless as to throw this concept out the window without at least pondering it’s validity a little bit more.

*Renowned mycologist Paul Stamets reliably sports one of his favorite garments, a hat made out of amadou, at many of his public lectures and presentations. A highly inspirational and informative talk in which Paul discusses both amadou and other mushrooms and their ability to improve the health of ourselves, our environment and even the health of bees can be viewed right here if the topic rouses your interest.