THE POLYPOBAOEAE OF WISCONSIN. 99 



Polyporus epileucus Pries. 



Pileus dimidiate, semicircular, concave below, at first cheesy-soft 

 later firm, but not fibrous within, shaggy-rough, whitish, subzonate; 

 pores small, round, entire, whitish. 



"Not uncommon on birch and willow, not likely to be mistaken for 

 any other species; when fresh soft, rather echinate above, when dry 

 very hard and heavy like putty" (Macbride, 15, p. 26). 



Not common. Specimens have been found near Blue Mounds, near 

 Madison and at Shanagolden on old logs and stumps. 



The largest specimens are about 10 em. wide, 6 cm. long and 1 to 1.5 

 cm. thick, the tubes being about three-fourths as long as the thickness 

 of the flesh. When fresh the specimens are of a pale yellowish white 

 color, cheesy-moist and almost leathery. The upper surface is uneven 

 and sometimes tubercular, sometimes nearly hispid. The pilei are 

 usually flat above, slightly convex below; sometimes sessile-dimidate ; 

 sometimes _eespitose. 



When dry the substance is hard and bony, heavy like putty, thus re- 

 sembling Polyporus osseus. The pores often contract and become torn 

 on drying. The shaggy pubescence often disappears with age, the 

 pilei becoming glabrate. 



Pol3T)orus gilvus Schw. 



Pileus corky, woody, dimidiate-sessile, or effused behind, yellow-fer- 

 ruginous, azonate, rough, uneven, the margin tomentose, acute; pores 

 very small, crowded, entire, brownish, changeable, context yellow-ferru- 

 ginous. 



"The pileus may remain thin," says Morgan (18 VIII, p. 105), "or 

 it may become excessively thick and subungulate ; the surface soon be- 

 comes scabrous, and sometimes it is furnished with warty granules; it 

 is often very uneven or scrupose. Specimens occur that are distinctly 

 zonate. The reddish-yellow of the growing margin soon changes to 

 ferruginous, and very old specimens have assumed a canescenee." 



Very common in the southern part of the state especially on dead 

 oak, but also on basswood, poplar, maple and hickory. Less abundant 

 in the northern part of the state where it is found on maple, elm and 

 basswood. The largest specimen is 12 cm. broad, 7 em. long, and 6 cm. 

 thick. Most of the specimens are quite thin. They are usually hard ; 

 the substance is rhubarb color, as is also the growing margin. The 

 young growth is usually quite tomentose ; sometimes the margin is ob- 



