WESTERN POLYPORES 25 



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

 hyaline, 5-6 X 4-5 /*. 



Frequent throughout on trunks and roots of various coniferous 

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

 hymenophores of this species usually occur in inconspicuous 

 places. 



3. 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 p. 



Common throughout on living trunks of conifers and less 

 frequent on deciduous trees growing near, causing a serious 

 disease. 



4. FOMES LARICIS (Jacq.) Murrill 



Pileus firm, at length fragile, ungulate to cylindric, 3-8 X 5-10 

 X 4-20 cm.; surface anoderm, powdery, white or slightly yellow- 

 ish, concentrically sulcate, becoming slightly encrusted, tubercu- 

 lose and rimose; margin obtuse, concolorous; context soft, tough, 

 at length friable, chalk-white or slightly yellowish, very bitter, 

 with the odor of fresh meal, 1-3 cm. thick; tubes evenly stratified, 

 concolorous, 5-10 mm. long each season, mouths circular to 

 angular, 3-4 to a mm., edges thin, fragile, white, becoming dis- 

 colored and lacerate, wearing away with age; spores ovoid, 

 5X4-"- 



Frequent throughout on dead or decayed trunks of fir, red fir, 

 spruce, hemlock, and pine. This species is much more abundant 

 in Europe and is there used in medicine because of the bitter, 

 resinous substance it contains. 



5. FOMES AMARUS (Hedgcock) Murrill, comb. nov. 



Polyporus amarus Hedgcock, Mycologia 2: 155. 1910. 



Pileus soft and spongy when young, becoming hard and chalky 

 when old, ungulate, often spuriously stipitate from knot-holes, 

 frequently large, 5-11 X 10-20 X 6-12 cm.; surface pubescent 

 when young, rimose and chalky when old, at first buff, becoming 

 tan and often blotched with brown when older; margin obtuse, 

 frequently having an outer band of darker brown, often slightly 



