368 Murrill: Polvporaceae of North America 



This abundant and variable species was transferred to Mucro- 

 noporus by Ellis on account of its spiny hymenium, but it is best 

 known as a Trametes. Besides its published specific names sev- 

 eral manuscript names have been assigned to it, among which are 

 Polyporus gausapatus Berk. & Rav. on pine, Dacdalca vorax Hark- 

 ness on Abies Douglasii in California and Dacdalca vetusta Ell. & 

 Hark., on white cedar in New Jersey. 



It seems that this plant is more sensitive to changes in host 

 than almost any other of its kind. One would expect a parasitic 

 species like this to show more variation than an ordinary dead- 

 wood species, but the forms here assumed on different hosts and 

 even on the same host under different conditions are surprising. 

 I am supposing that the range of forms found on pine, spruce and 

 other conifers represent a single species. They have all seemed 

 so to me, and Dr. Schrenk expects shortly to prove their identity 

 by the completion of a series of inoculation experiments covering 

 various hosts. 



The present species is too well known throughout both Europe 

 and America as a destructive parasite of coniferous trees to re- 

 quire a list of specimens collected. All published exsiccati cover- 

 ing the group contain it and fresh material may be gathered in 

 almost any locality. 



6. ELFVINGIA Karst. Finlands Basidsv. 333. 1889. 



Type: Elfvingia lips ic us is (Batsch) Murr. 

 Xylopilus Karst. Bidr. Finlands Nat. och Folk 37: 69. 1882. 



Type : Xylopilus crassus (Fr.) Karst. 



Hymenophore large, epixylous, sessile, applanate or ungulate ; 

 surface sulcate, horny-encrusted : context brown, punky ; tubes 

 brown, cylindrical, stratose, thick-walled, mouths whitish when 

 young : spores brown, rarely hyaline ; conidia present in most 

 species on the surface of the pileus. 



Species: E. fomentaria (L.) Murr., E . fasciata (Sw.) Murr., 

 E. rcuifonuis (Morg.) Murr., E. megaloma (Lev.) Murr., E. tornata 

 (Pers.) Murr., E. Liouuctii (Rolland) Murr. [see Bull. Torrey 

 Club 30: 296-301. 1903]. 



An examination of Schweinitz' type has shown his Polyporus 

 lobatus to be a somewhat distorted form of Elfviugia rcuiforuris. 

 P. lobatus Schw. is not tenable, however, because of P. lobatus 

 Schrad. 



