106 THE POLYPORACEAE OF WISCONSIN. 



Madison growing at the base of a living oak tree ; at Blue Mounds and 

 at Crandon, growing on the roots of small tamaracks. Most of the 

 specimens are some shade of gray, but sometimes they are while 

 throughout. 



P. frondosus differs from the other white Merismatae in the abund- 

 ant branching and interlacing of the stems. The substance of the stems 

 and pileoli is soft leathery and tough. When young and growing vig- 

 orously the pileoli are not rugose but smooth. 



The pores are snow-white, delicate, as large as those of P. sulphur eus, 

 and usually lacerate. The pilei are attached laterally to the stipe and 

 thus differ from those of P. umbellatus. 



Syn.: Grifolia frondosa (Dicks.) S. F. Gray; 19, 31, p. 336. 

 Polypilus frondosus (Dicks.) Karst. ; 13, 3, p. 17. 



Polyporus umbellatus (Pers.) Fr. 



Pilei numerous, more or less depressed, umbilicate, 1 to 4 cm. in di- 

 ameter, entire, or the larger ones lobed and cut, of fibrous-fleshy sub- 

 stance, somewhat tough, united to form tufts one span high. Stems 

 lengthened, separate but united at the base, white like the small un- 

 equal pores. On the ground under deciduous trees and at the base of 

 trunks. 



Not common. One tuft was collected by Mr. B. 0. Dodge near Al- 

 goma. It measures about 10 cm. in diameter, and is made up of nu- 

 merous small more or less central-stemmed pileoli. These pileoli are 

 thin, umbilicate, more or less circular and measure about 2 to 2.5 cm. 

 in diameter. The stipes vary from 5 to 8 em. in length and from about 

 5 to 8 mm. in thickness. When dry the whole plant is of a brownish- 

 gray color. It has also been found at Devils Lake and Parf rev's Glen. 



The species is closely related to P. frondosus, with which it is some- 

 times confused. However, it can easily be distinguished from that 

 species by the fact that the pileoli are more or less central-stemmed and 

 umbilicate. 



Syn.: Grifolia ramosissima (Scop.) Murr. ; 19, 31, p. 336. 

 Boletus umbellatus Pers. ; 23, p. 519. 



Polyporus cristatus (Pers.) Fr. 



Branching, fleshy-solid, fragile ; pilei entire and dimidiate, imbricate, 

 depressed, subpulverulent- villous, finally rimose scaly, greenish tawny ; 

 stipes, connate irregular, white; pores minute, angular and lacerate, 

 whitish. 



