Though inedible, F. fomentarius has traditionally seen use as the main ingredient of
Ötzi the Iceman
carried four pieces of F. fomentarius, concluded to be for use as tinder. It also has medicinal and other uses.
Taxonomy
The first scientific description of the fungus appeared in the literature in the 1753
specific epithet fomentarius is from the Latinfomentum, referring to tinder.[5] The species has been described as a member of numerous different genera. In 1783, Jean-Baptiste Lamarck named the species Agaricus fomentarius in his Encyclopédie Méthodique: Botanique.[6] In 1818, Georg Friedrich Wilhelm Meyer described Polyporus fomentarius in his Primitiae Florae Essequeboensis,[7] and this name was sanctioned by Elias Magnus Fries in the 1821 publication of the first volume of his Systema Mycologicum.[2] Fries later, in his 1849 Summa vegetabilium Scandinaviae, moved the species to the genus Fomes. Subsequent attempts to change the genus of the species have been unsuccessful; the species was named Placodes fomentarius by Lucien Quélet in 1886, Ochroporus fomentarius by Joseph Schröter in 1888 and Scindalma fomentarium by Otto Kuntze in 1898. In the twentieth century, Narcisse Théophile Patouillard named the species Ungulina fomentaria in 1900, and William Murrill twice reallocated the species; in 1903, he named it Elfvingia fomentaria and in 1914, he named it Elfvingiella fomentaria. In 1963, Shu Chün Teng named it Pyropolyporus fomentarius. 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.[2] The species is commonly known as the tinder fungus, hoof fungus,[3] tinder polypore, ice man fungus[8] or false tinder fungus.[9]
Description
F. fomentarius can vary in colour from a very light grey to almost black.
Fomes fomentarius has a
bracket-like with an umbonate attachment to the substrate.[10] The species typically has broad, concentric ridges, with a blunt and rounded margin.[10] The flesh is hard and fibrous, and a cinnamon brown colour.[3] The upper surface is tough, bumpy,[10] hard and woody,[3] varying in colour, usually a light brown or grey. The margin is whitish during periods of growth.[10] The hard crust is from 1 to 2 mm (0.04 to 0.08 in) thick, and covers the tough flesh.[11] The underside has round pores of a cream colour when new, maturing to brown,[10] though they darken when handled.[3] 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.[3]
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".[12]
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.[13]
Though initially parasitic, F. fomentarius continues to grow upon fallen trees.
Fomes fomentarius is a
saprotrophic feeder,[17] and typically lives there for years, until the log is completely destroyed.[18] It is also capable of colonising and breaking down pollen grains, giving it a second food source which is particular high in nitrogen.[13] Infected trees become very brittle,[19] 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.[18] 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.[8]
The fruit bodies are
basidiospores an hour being produced by some fruit bodies. Spore production also takes place in autumn, though not nearly as heavily.[12] The spores are released at comparatively low temperatures.[22] In dry weather, the spores are visible as a white powder.[11]
Ötzi the Iceman was carrying four pieces of F. fomentarius fruit body.[27] Chemical tests led to the conclusion that he carried it for use as tinder.[28]
