1915] 



OVERHOLTS STUDIES IN THE POLYPORACEAE 717 





observers have stated that they have been unable to find setae 

 in the hymenium of F. nigricans. 



The original illustration of F. nigricans does not agree with 

 any present-day conception of what the species really was. 

 The manner in which the plates for Fries ' ' Icones ' were gotten 

 together does not at all preclude the existence of grave errors 

 regarding the identity of the species there illustrated. Hence 

 the original illustration of F. nigricans has been discounted by 

 careful European workers, they preferring to base the species 

 rather on specimens authenticated by Fries himself. Of these, 

 there appear to be specimens both at Upsala and at Kew. 



The F. nigricans of my 'Ohio Polyporaceae ' proves to be 

 F. Baheri Murrill. The specimens referred by me to F. 

 igniarius are of two types. One of these has the pileus convex 

 or ungulate, the surface sometimes becoming rimose, and 

 setae not at all abundant. The second type is most commonly 

 found on birch trees. The pileus is plane or slightly convex, 

 sometimes shining black in color, and the surface often cracks 

 in both directions but does not become roughly rimose. The 

 setae are often more abundant. Of this second form, Lloyd 

 recently wrote as follows concerning a collection sent to him 

 by me: "It agrees with his (Fries') specimens (of F. nigri- 



cans) both at Upsala and at Kew It is usually thinner 



than typical F. igniarius and the setae are more abundant 

 than in the type form. ' ' 



On the strength of this information I am now able to 

 separate my collections of these forms into what I am con- 

 vinced are the two species, F. igniarius and F. nigricans, re- 

 spectively. I have examined all available material of the two 

 species and have thoroughly confirmed Romell's observation 

 on the presence of the setae. In but one collection was I un- 

 able to find setae and I do not doubt that further attempts 

 would show their presence in that instance. It is advisable, 

 however, as stated on a previous page of this article, to cut 

 longitudinal sections of the hymenium, since by so doing one 

 will be more likely to strike the setae if there is any variation 

 in their abundance at particular places in the tubes. 



