PORIA 369 



As the mycelium always spreads very extensively before 

 sporophores appear, any attempt at cure is hopeless, and the 

 only thing to do is to cut down and remove diseased trees. 



Trametes suaveolens (Fries.). Occurs on willows, but does 

 comparatively no injury. 



Smell resembling aniseed. Pileus whitish, downy, 3-6 in. 

 across, flesh white, corky; tubes \ in. or more in length, 

 pores large, irregularly rounded. 



PORIA (PERS.) 



Entirely resupinate, often forming large patches, covered 

 with the pores or hymenium, flesh thin, often almost absent. 



The numerous species are mostly saprophytic on fallen 

 wood or branches, and many are in all probability only reduced 

 conditions of Fomes or Polyporus, 



Poria vaporaria (Fr.) is probably the most abundant and 

 most generally distributed of polyporus fungi. As a sapro- 

 phyte it is present on practically every other fallen branch 

 throughout the kingdom. In addition it sometimes assumes 

 a parasitic life, entering through wounds caused by the 

 nibbling of various animals, etc. Conifers are most fre- 

 quently attacked, and the wood becomes reddish-brown, 

 cracked, and dry. The mycelium forms sheets in cracks of 

 the wood, or between the wood and the bark under the form 

 of branched, woolly strands, much resembling those of the 

 dry-rot fungus (Merulius lacrymans) from which they can be 

 readily distinguished by remaining pure white, instead of 

 changing soon to a dull grey colour. In addition the fungus 

 often does considerable injury to worked timber, more especi- 

 ally when exposed to damp as in greenhouses, etc., and in 

 such positions may at first be mistaken for dry-rot, but can 

 be distinguished by the colour of the mycelium as already 

 stated, and by the distinct white pores when in a fruiting 

 condition. 



Broadly effused, thin, inseparable from the matrix ; pores 

 large, angular or wavy, white, then yellowish. 



When worked timber is attacked the treatment recom- 

 mended for dry-rot should be followed. 



.- Poria subacida (Peck) is stated by Schrenk as probably 

 being one of the species causing injury to living conifers ; it 

 is certainly an active destroyer of dead timber. This species 

 is recognised in the forest by the copious formation of masses 



2 A 



