44 



NORTHERN POLYPORES 



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



Tubes i2 mm. long each season; spores ellipsoid. i. F. roseus. 



Tubes 3-5 mm. long each season; spores globose. 2. F. fraxineus. 



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. 3. F. ohiensis. 



Pileus scutellate, uniformly black even when young; 

 tubes less than 2 mm. long, context thinner than 

 the tube-layer. 4. F. scutellatus. 



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. 5. F.annosus. 



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. 6. F, Rllisianus. 



Surface not as above. 



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

 often resinous, bay or black in color; 

 abundant on conifers. 7. F. ungulatus. 



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. 8. F. fraxinophilus. 



Pileus rarely encrusted, surface concolorous with the 



context. 



Pileus chalk-white or slightly yellowish through- 

 out, cylindric; context friable, bitter; growing 

 on conifers. 9. F. Laricis. 



Pileus not as above; growing on deciduous trees. 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 /j,. 



Common throughout on living or dead trunks of conifers, and 

 occasionally on deciduous trees, causing a serious rot. The 



