42 THE POLYPORACEAE OF WISCONSIN. 



base. It is white to pale tawny, the old parts becoining black, and 

 the context, at first white, becomes darker wood-color and never very 

 thick. It is usually more or less glabrate, zoned, often concentrically 

 sulcate ; the white margin smooth, more or less acute, spreading. The 

 hymenium is white or pale tawny and nearly always concave. The 

 pores are small even, regular, with thick dissepiments. The tubes are 

 of unequal length. 



Some of the older specimens seem to be quite distinctly stratified, 

 and look like No. 1010 of Fungi Columbiani {Fomes scutellata). Per- 

 haps the two forms should be placed together in the genus Fomes. T. 

 scutellata is said by Macbride (15, p. 10) to be the same as Trametes 

 Ohiensis Berk. 



An entirely resupinate form occurs on the underside of old fence 

 rails. This is dry, whitish, thin, closely incrusting the surface of the 

 wood. The tubes are short with small mouths and thick dissepiments. 

 The hymenium is the same as that of the dimidiate forms. The pileus 

 follows the unevenness of the wood surface, with here and there slight 

 indications of becoming reflexed. This is not always evident, however. 



T. scutellata is a quite common form growing on old fence rails 

 and posts. I have never seen it on trees and logs lying on the ground. 

 Specimens have been collected in Monroe, Walworth, Dane, Fond du 

 Lac, Dodge, Iowa and La Crosse Counties. They are from 2 to 3 cm. 

 wide ; 1 to 4 cm. long ; flesh 4 to 6 mm. thick. The tubes are 1 mm. 

 long in resupinate forms, and in others form 3 to 10 mm. 



The distinguishing characteristics of the species are the hoof -shaped 

 pileus, the white dry substance, the concave hymenium with small 

 pores and thick dissepiments. 



Syn. Fomes scutellatus (Schw.) ; 26, vol. VI, p. 192. 

 Trametes oJiiensis Berk. ; 26, vol. VI, p. 342. 



§2. Context yellowisJi. 



Trametes rigida B. & Mont. 



Pileus corky, undulate, by far the greater part resupinate ; the mar- 

 gin narrow, acute, subzonate, tawny brown; pores medium, round, 

 equal, obtuse, whitish. 



Only a resupinate form was found growing on the underside !)f 

 a poplar log at Madison. The specimen was about 15 cm. long, 2 to 4 

 cm. wide, and nearly 1 cm. thick. The color varied from whitish to 

 tawny. The substance was quite hard and tough. 



