30 THE POLYPORACEAE OF WISCONSIN. 



4. GLOEOPORUS Mont. 



Pileus with a coriaceous, floccoso-eellulose context, usually white. 

 The distinctive characteristic is the tremelline-gelatinous hymenium 

 with its at first punctiform impressions and which contracts on drying. 



Gloeoporus conchoides Mont. (Plate I, fig. 5). 



Conchiform, pileus coriaceous, thin, pliant, dimidiate, sessile, convex, 

 unequal, velutinous then somewhat glabrate, tawny, margin acute; 

 pores flesh-colored, white when wet, round, minute, superficial, gelat- 

 inous. 



"Pileus varies from white to tawny; from dimidiate to resupinate. 

 Appeared to Berkeley and Cooke to be a form of P. nigropurpurascens 

 Schw. or P. dichrous Fr." (Sac., 26, vol. 6, p. 403). 



This species seems to be quite common on decayed poplar logs, run- 

 ning lengthwise and laterally confluent, like P. adustus, and may cover 

 the whole side of the log. It grows in late summer and fall, even after 

 frost has come. 



When young the hymenium is markedly gelatinous. This charac- 

 ter, however, is entirely lost when eld. The pores become brown elon- 

 gated tubes, sometimes 1 cm. in length. 



The pilei are either dimidiate and sessile or strongly reflexed ; cor- 

 iaceous, thin with a thick base ; veiy convex above and concave below 

 and hence said to be conchiform. The margin is acute, uneven and 

 usually lighter when growing. 



The pores are at first small, roundish, shallow, unequal, apparently 

 formed by folds of the hymenium. When moist and growing, the 

 hymenium is white-primrose ; otherwise it is of a dark-brownish purple 

 near the base becoming lighter toward the margin where it may be 

 almost orange, especially in growing specimens. 



Old specimens of both G. conchoides and Merulius tremellosus were 

 found at Elkhorn and carefully compared. From some specimens the 

 hymenium had rotted or been eaten away. On the underside of the 

 pileus of Merulius tremellosus were found reddish radiating fibres, 

 probably the bundles of mycelial hyphae which go to form the hy- 

 menium as mentioned above. Under the grayish weathered pilei of 

 Gloeoporus conchoides these red fibres are not found. The underside 

 is smooth, gray to grayish white. 



G. candidus Speg. is closely related. It is thinner and the hy- 

 menium is very much lighter in color. It may be only a variety of 

 G. conchoides. 



