70 THE POLYPORACEAE OF *\YIKCOXSIX. 



10. FOMES Fries. 



This genus is characterized by its woody-indurated pileus, (rarely 

 soft), floccose interwoven texture, covered with a rigid crust, azonate 

 at first but becoming concentrically sulcate; perennial, the successive 

 strata being formed by the further growth from the surface of the last 

 formed stratum. 



Here is where the large, hard, woody bracket fungi belong, easily 

 recognizable by their hard crust and stratified pores. 



A number of closely related species having their tubes lined with 

 spines and spinules are placed by some authors in the genus Mucrono- 

 porns E. & Ev., but are here retained in the genus Fomes. 



KEY TO WISCONSIN SPECIES OF FOMES 



1. Stipitate, laccate F. lucidus 



2. Sessile 



a. Substance dark-brown F. applanatus 



F. fomentarius 



b. Substance rust-colored F. Everhartii 



F. Bakeri 



F. igniarius 



F. nigricans 



F. rimosus 



F. concnatus. 



F. ribis 



c. Rose-colored F. carneus 



F. roseus 



d. White or pale F. ungulatus 



F. marginatus 



F. populinus 



F. connatus 



F. officinalis 



3. Resupinate-reflexed F. salicinus 



§1. Ligxosi. Hard, lignose, covered ivith a iJiin rind. 



Fomes populinus Fries. 



White, pileus between corky and woody, rigid, zoneless, villose, mar- 

 gin obtuse; white within; pores minute, short, rounded. 



Rare. Collected on dead Populas tremuloidies. The largest speci- 

 men is about 6 cm. broad, 4 cm. long and 2 cm. thick. Most of them, 

 however, are smaller. The pilei are imbricated and grown together 



