46 NORTHERN POLYPORES 



Frequent in the eastern United States westward to Iowa on 

 dead branches and timbers of alder, witch hazel, and other 

 deciduous trees and shrubs. 



5. FOMES ANNOSUS (Fries) Cooke 



Pileus woody, dimidiate, very irregular, conchate to applanate, 

 10-13 X 5-8 X 0.5-2 cm.; surface at first velvety, rugose, 

 anoderm, light-brown, becoming thinly encrusted, zonate, and 

 finally black with age; margin pallid, acute, becoming thicker; 

 context soft-corky to woody, white, 0.3-0.5 cm. thick; tubes 

 unevenly stratified, 2-8 mm. long each season, white, mouths 

 subcircular to irregular, 3-4 to a mm., edges rather thin, entire, 

 firm, white, unchanging; spores subglobose or ellipsoid, smooth, 

 hyaline, 5-6 X 4-5 M- 



Common throughout on trunks and roots of various coniferous 

 trees, and rarely on deciduous trees, causing serious decay. 



6. FOMES ELLISIANUS F. W. Anderson 



Pileus dimidiate, ungulate, woody, 4-7 X 6-8 X 2-5 cm.; 

 surface radiate-rugose, sulcate, light-bay or brown, becoming 

 rimose and darker with age; margin obtuse or rounded, pallid, 

 fertile; context corky, pale-ochraceous, 0.5-1 cm. thick, becoming 

 scanty in the older sporophores; tubes indistinctly stratified, 

 concolorous with the context, fragile, 0.5-1 .5 cm. long each season, 

 mouths subcircular, 3 to a mm., edges rather thick, pruinose when 

 young, becoming concolorous; spores ovoid to slightly oblong, 

 smooth, 5-6 X 4-5 M. 



Occasional on living trunks and branches of Shepherdia argentea 

 in South Dakota, as well as in Montana, Colorado, and New 

 Mexico. Very near Fomes fraxinophihis . 



7. FOMES UNGULATUS (Schaeff.) Sacc. 



Pileus corky to woody, ungulate, 8-15 X 12-40 X 6-10 cm.; 

 surface glabrous, sulcate, reddish-brown to gray or black, often 

 resinous; margin at first acute to tumid, pallid, becoming yellow- 

 ish or reddish-chestnut; context woody, pallid, 0.5-1 cm. thick; 

 tubes distinctly stratified, 3-5 mm. long each season, white to 

 isabelline, mouths circular, 3-5 to a mm., edges obtuse, white to 

 cream-colored; spores ovoid, smooth, 6 /j.. 



Extremely common throughout on living trunks of conifers 

 and less frequent on deciduous trees growing near, causing a 

 serious disease. 



