FOMES 371 



here and there ; pores shallow, circular or irregular, bright 

 citron-yellow, minute; spores 5x2^5 /x 



FOMES (Fries.) 



Perennial. Pileus thick, bracket or hoof-shaped, hard and 

 woody, often with concentrical ridges, not colour-zoned ; 

 tubes stratified, the external stratum of tubes alone producing 

 spores. 



Conidial forms are known in some species. 



Amongst the largest and most persistent of fungi, many 

 species are destructive parasites on trees. 



The tinder fungus (Pomes fomentarius, Fries.) is one of 

 our most destructive wound-parasites, attacking many kinds 

 of trees, as beech, elm, and various fruit-trees. It does not 

 attack conifers. The large, hard, bracket-like, fruiting bodies 

 only appear on the surface of the trunk of the tree after the 

 mycelium has been present in the wood for some considerable 

 time. The effect produced by the mycelium on the wood 

 has been termed white-rot by Hartig, on account of the heart- 

 wood which is first attacked assuming a white colour, and 

 becoming broken up into cubes by the action of the mycelium. 

 As decay proceeds, thin, skin-like layers of mycelium, resemb- 

 ling kid leather, are formed in the cracks in the wood ; these 

 sheets grow outwards towards the bark, and at length give 

 origin to the external fruiting bodies. Tubeuf says that the 

 marked depression or groove in the trunk above and below 

 the fruiting bodies is due to the mycelium of the fungus 

 having destroyed the cambium, and thus prevented the 

 further formation of wood at these parts. Hoof-shaped, thick, 

 4-8 in. across, 4-6 in. thick, concentrically grooved, brown, 

 margin whitish, especially when young. Flesh thick, rather 

 soft, brown. Tubes long, stratose, rusty, pores white, then 

 brown ; spores brown, 6 x 3 '5-4 /^. 



The section of entire fungus is more or less triangular. 

 The surface of the pileus is covered with a snuff-coloured 

 powder a conidial form of reproduction which distinguishes 

 this from allied species. For further distinctions from other 

 species, see remarks under P. igniarius (Fr.). 



At one time the soft brown, fleshy portion of this fungus 

 was used for tinder. At a later period the flesh, after being 

 cut into sections and specially prepared, furnished large sheets 



