44 



NORTHERN POLYPORES 



Context flesh-colored; light-brown in faded specimens. 

 Tubes 1-2 mm. long each season; spores ellipsoid. 

 Tubes 3-5 mm. long each season; spores globose. 

 Context white or nearly so. 

 Pileus less than 3 cm. broad. 



Pileus ungulate, becoming black only at the base, 

 zonate and concentrically sulcate in age; tubes 

 over 2 mm. long. 



Pileus scutellate, uniformly black even when young; 

 tubes less than 2 mm. long, context thinner than 

 the tube-layer. 

 Pileus more than 3 cm. broad. 



Pileus encrusted, surface darker than the context. 

 Pileus thin, distinctly zonate, irregular or appla- 



nate; crust brown to black. 



Pileus thick, sulcate, ungulate, rarely applanate. 

 Surface soon becoming rimose, deeply sulcate; 

 older pores visible in the upper projecting 

 annual layers; pileus exactly ungulate; 

 found only on Shepherdia. 

 Surface not as above. 



Mouths of tubes 4-5 to a mm.; surface 

 often resinous, bay or black in color; 

 abundant on conifers. 



Mouths of tubes 2-3 to a mm.; surface 

 gray to black, never resinous nor red- 

 dish; found only on ash and a few other 

 deciduous trees. 

 Pileus rarely encrusted, surface concolorous with the 



context. 



Pileus chalk-white or slightly yellowish through- 

 out, cylindric; context friable, bitter; growing 

 on conifers. 

 Pileus not as above; growing on deciduous trees. 



1. F. roseus. 



2. F. fraxineus. 



3. F. ohiensis. 



4. F. scutellatus. 



5. F. annosus. 



6. F. Ellisianus. 



7. F. ungulatus. 



8. F. fraxinophilus. 



9. F. Laricis. 

 10. F. populinus. 



i. FOMES ROSEUS (Alb. & Schw.) Cooke 



Pileus woody, dimidiate, varying from conchate to ungulate, 

 often imbricate and longitudinally effused, 2-4 X 6-8 X 0.5-3 

 cm.; surface rugose, subfasciate, slightly sulcate, rosy or flesh- 

 colored, becoming gray or black with age; margin acute, becoming 

 obtuse, sterile, pallid, often undulate; context floccose-fibrose to 

 corky, rose-colored, 0.2-2 cm. thick; tubes indistinctly stratose, 

 1-2 mm. long each season, mouths circular, 3-4 to a mm., edges 

 obtuse, concolorous; spores ellipsoid, smooth, thick-walled, 

 subhyaline, 3.5 X 6 /*. 



Common throughout on living or dead trunks of conifers, and 

 occasionally on deciduous trees, causing a serious rot. The 



