(L.) Fr. 1849
Fomes fomentarius (commonly known as the tinder fungus, false tinder fungus, hoof fungus, tinder conk, tinder polypore or ice man fungus) is a species of fungal plant pathogen found in Europe, Asia, Africa and North America. The species produces very large polypore fruit bodies which are shaped like a horse's hoof and vary in colour from a silvery grey to almost black, though they are normally brown. It grows on the side of various species of tree, which it infects through broken bark, causing rot. The species typically continues to live on trees long after they have died, changing from a parasite to a decomposer.
Though inedible, F. fomentarius has traditionally seen use as the main ingredient of amadou, a material used primarily as tinder, but also used to make clothing and other items. The 5,000-year-old Ötzi the Iceman carried four pieces of F. fomentarius, concluded to be for use as tinder. It also has medicinal and other uses. The species is both a pest and useful in timber production.
- Taxonomy 1
- Microscopic features 2.1
- Similar species 2.2
- Habitat and distribution 3
- Ecology 4
Uses and importance 5
- Amadou 5.1
- See also 6
- References 7
- Cited texts 8
- External links 9
The first scientific description of the fungus appeared in the literature in the 1753
The species is well known for its uses in making fire. This species, as well as others, such as Phellinus igniarius, can be used to make amadou, a tinder. Amadou is produced from the flesh of the fruit bodies. The young fruit bodies are soaked in water before being cut into strips, and are then beaten and stretched, separating the fibres. The resulting material is referred to as "red amadou". The addition of gunpowder or nitre produced an even more potent tinder. The flesh was further used to produce clothing, including caps, gloves and breeches. Amadou was used medicinally by dentists, who used it to dry teeth, and surgeons, who used it as a styptic. It is still used today in fly fishing for drying the flies. Other items of clothing and even picture frames and ornaments have been known to be made from the fungus in Europe, particularly Bohemia. The fungus is known to have been used as a firestarter in Hedeby, and it is known that the fungus was used as early as 3000 BCE. When found, the 5,000-year-old Ötzi the Iceman was carrying four pieces of F. fomentarius fruit body. Chemical tests led to the conclusion that he carried it for use as tinder.
The species is not considered edible; the flesh has an acrid taste, with a slightly fruity smell. The fungus has economic significance as it removes any timber value of infected trees. As Fomes fomentarius infects trees through damaged bark, it will often infect trees already weakened from beech bark disease. However, it is too weakly parasitic to infect healthy trees, and thus has the important and useful role of decomposing unusable timber.
Uses and importance
The fruit bodies are perennial, surviving for up to thirty years. The strongest growth period is between early summer and autumn. The yearly growth always occurs on the bottom of the fungus, meaning that the lowest layer is the youngest. This occurs even if the host tree has been laid on the forest floor, which can happen because of the white rot induced by the fungus. This is a process known as positive gravitropism. Very large numbers of spores are produced, particularly in spring, with up to 887 million basidiospores an hour being produced by some fruit bodies. Spore production also takes place in autumn, though not nearly as heavily. The spores are released at comparatively low temperatures. In dry weather, the spores are visible as a white powder.
Fomes fomentarius is a stem decay plant pathogen. The species' mycelium penetrates the wood of trees through damaged bark or broken branches, causing rot in the host. It can grow on the bark wound, or even directly onto the bark of older or dead trees. The decayed wood shows black lines in the lightly coloured decayed areas; these are known as pseudosclerotic layers or demarcation lines. The lines are caused by enzymes called phenoloxidases, converting either fungus or plant matter into melanin. The lines are not an absolute identifier, as they can also occur in plants infected by Kretzschmaria deusta and some Armillaria species. Despite beginning as a parasite, the species is able to survive for a time (hastening decomposition) on fallen or felled trees as a saprotrophic feeder, and typically lives there for years, until the log is completely destroyed. It is also capable of colonising and breaking down pollen grains, giving it a second food source which is particular high in nitrogen. Infected trees become very brittle, and cracks can occur in the affected tree due to wind. F. fomentarius is particularly adept at moving between cracks on the tree without interruption. However, in addition to the obviously infected damaged trees, F. fomentarius is known to be an endophyte, meaning that healthy trees which are not sporting F. fomentarius fruit bodies could still be infected.
F. fomentarius has a circumboreal distribution, being found in both northern and southern Africa, throughout Asia and into eastern North America, and throughout Europe, and is frequently encountered. The optimal temperature for the species's growth is between 27 and 30 °C (81 and 86 °F) and the maximum is between 34 and 38 °C (93 and 100 °F). F. fomentarius typically grows alone, but multiple fruit bodies can sometimes be found upon the same host trunk. The species most typically grows upon hardwoods. In northern areas, it is most common on birch, while, in the south, beech is more typical. In the Mediterranean, oak is the typical host. The species has also been known to grow upon maple, cherry, hickory, lime tree, poplar, willow, alder, hornbeam, sycamore, and even, exceptionally, softwoods, such as conifers.
Habitat and distribution
Fomes fomentarius can easily be confused with Phellinus igniarius, species from the genus Ganoderma and Fomitopsis pinicola. An easy way to differentiate F. fomentarius is by adding a drop of potassium hydroxide onto a small piece of the fruit body from the upper surface. The solution will turn a dark blood red if the specimen is F. fomentarius, due to the presence of the chemical fomentariol.
The spores are lemon-yellow in colour, and oblong-ellipsoid in shape. They measure 15–20 by 5–7 μm. The species has a trimitic hyphal structure (meaning that it has generative, skeletal and binding hyphae), with generative hyphae (hyphae that are relatively undifferentiated and can develop reproductive structures) with clamp connections.
The colouration and size of the fruit body can vary based on where the specimen has grown. Silvery-white, greyish and nearly black specimens have been known. The darkest fruit bodies were previously classified as Fomes nigricans, but this is now recognised as a synonym of Fomes fomentarius. The colour is typically lighter at lower latitudes and altitudes, as well as on fruit bodies in the Northern Hemisphere that grow on the south side of trees. However, studies have concluded that there is no reliable way to differentiate varieties; instead, the phenotypic differences can "be attributed either to different ecotypes or to interactions between the genotype and its environment".
Fomes fomentarius has a fruit body of between 5 and 45 centimetres (2.0 and 17.7 in) across, 3 and 25 cm (1.2 and 9.8 in) wide and 2 and 25 cm (0.8 and 9.8 in) thick, which attaches broadly to the tree on which the fungus is growing. While typically shaped like a horse's hoof, it can also be more bracket-like with an umbonate attachment to the substrate. The species typically has broad, concentric ridges, with a blunt and rounded margin. The flesh is hard and fibrous, and a cinnamon brown colour. The upper surface is tough, bumpy, hard and woody, varying in colour, usually a light brown or grey. The margin is whitish during periods of growth. The hard crust is from 1 to 2 mm (0.04 to 0.08 in) thick, and covers the tough flesh. The underside has round pores of a cream colour when new, maturing to brown, though they darken when handled. The pores are circular, and there are 2–3 per millimetre. The tubes are 2 to 7 mm (0.08 to 0.28 in) long and a rusty brown colour.
 or false tinder fungus. tinder polypore, ice man fungus as the tinder fungus, hoof fungus,commonly known The species is . These names are considered obligate synonyms; that is, different names for the same species based on a single description or specimen. In addition to the obligate synonyms, there are a number of taxonomic synonyms, whereby names have been described as separate species, but have come to be considered synonymous.Pyropolyporus fomentarius named it Shu Chün Teng. In 1963, Elfvingiella fomentaria and in 1914, he named it Elfvingia fomentaria twice reallocated the species; in 1903, he named it William Murrill in 1900, and Ungulina fomentaria named the species Narcisse Théophile Patouillard in 1898. In the twentieth century, Otto Kuntze by Scindalma fomentarium in 1888 and Joseph Schröter by Ochroporus fomentarius in 1886, Lucien Quélet by Placodes fomentarius. Subsequent attempts to change the genus of the species have been unsuccessful; the species was named Fomes, moved the species to the genus Summa vegetabilium Scandinaviae Fries later, in his 1849 .Systema Mycologicum in the 1821 publication of the first volume of his Elias Magnus Fries by sanctioned and this name was