36 THE POLYPORACEAE OF WISCONSIN. 



as a trama between the pores in such a fashion as to suggest a Trametes 

 and the context is delicately zoned. ' ' 



This is one of our handsomest and most showy polypores. It is easily 

 recognized by its massive structure, very obtuse margin; straw-yellow, 

 tomentose or rough velvety surface; very large sinuous pores which 

 sometimes reach a length of from 3 to 3.5 cm. The substance is corky- 

 fibrous. Part of these fibres pass down into the trama, and part up- 

 ward into the pubescence. I have seen none that are glabrate. When 

 old and weathered the pileus cracks and forms bunches of stiff hairs 

 which become gray or blackish. The flesh is pale alutaceous as are 

 nlso the pores. The latter become darker on drying. 



Specimens vary much in size. My largest specimen measures about 

 24 cm. in width and 15 cm. in length. The flesh of the pileus is 4 cm. 

 in thickness and the tubes vary from 3 to nearly 4 cm. in length. The 

 figure shows part of the hymenium of a specimen enlarged and is a 

 good representation of the labyrinthine pores. 



The specimens are usually sessile dimidiate or crescent-shaped, grow- 

 ing backward so that they seem to clasp the tree upon which they 

 grow. Two specimens were collected by Mr. F. E. McKenna in Iowa 

 County. These are orbicular, growing from the underside of a fence 

 rail. The pores are closed or stuffed in these. This is a common con- 

 dition in younger specimens. 



Quite common on dead or living black oak and hickory trees. Speci- 

 mens have been collected in Dane, Walworth, Iowa, Monroe, LaCrosse, 

 and Chippewa Counties. 



Berkeley describes the species as ''thin," but our specimens never 

 appear so; they are always thick. The long tubes and the incurved 

 margin make the species thick pulvinate and obtuse. 



Syn. Polyporus obtusus (Berk) ; 26, vol. VI, p. 134; 15, p. 22. 

 Trametes unicolor (Schw.) Murrill; 19, vol. 32, p. 638. 

 Polyporus unicolor Schweinitz ; 26, vol. VI, p. 131. 



7. TRAMETES Fries. 



Fries describes the genus as follows: Pores subrotund, obtuse, en- 

 tire, usually of equal depth not forming a heterogeneous stratum, ap- 

 pearing as if sunk into the flesh of the pileus; the trama continuous 

 with the flesh of the pileus and similar to it. From woody to suberose, 

 hard, not stratose, commonly scented. 



The most prominent characteristics of this genus are the lignatile 

 pileus, the pores, with obtuse dissepiments, which are usually subro- 



