Murrill: Polyporaceae of North America 298 



1. Elfvingia fomentaria (L.) 



Boletus fomentarius \.. S^. PI. 1 176. 1753. 

 Boletus unguhxtus Bull. Herb. France,/'/. 4c) i. fig. 2, C. D. E. 

 Polyporus fouicutarius Yx. Syst. i : 374. 1821. 

 Fo)ucs fouioitarins Gill. Champ. Vx. i : 686. 1878 ; Icon. 

 467. 



See also Sowerby, Engl. Fungi, //. /??, and Schaeffer, //. 



137- 



Thi.s fungus is widely distributed on birch and beech in the 



temperate regions of Furope and North America. It varies little 

 in shape and appearance in the north, though very small forms 

 occur in high latitudes. One of these brought from the Isle a 

 la Crosse by Dr. Richardson was described by Berkeley as var. 

 excavatus (Ann. Nat. Hist. 3: 387. 1839). The type specimens 

 at Kew agree in all respects with P. fouicutarius as it grows in the 

 Adirondack Mountains and in Sweden. A more southern form, 

 larger, thicker, more uniform and ashy in color, is known in 

 Europe as Polyporus luacugae De Not., but as this does not occur 

 in North America it need not be discussed at present. When 

 fruit-bodies of P. fouicutarius become old and indurated and lose 

 their outer pellicle the horny crust takes a high ivory-black polish 

 and is very different from the usual covering of the plant. It is 

 this form that has frequently been mistaken for P. nigricaus Fr. 

 At Kew, P. igniarius and P. applanatus have been variously con- 

 fused with P. fomcutarius. 



In addition to the usual European and American exsiccati, all 

 of which contain this species, material has been examined from 

 Germany (Magnus), Sweden (Murrill), France (Patouillard), Fin- 

 land (Karsten), Italy (Bresadola), Scotland (Klotsch), Canada 

 (Macoun), Maine (Ricker), New Hampshire (Miss Minns), Massa- 

 chusetts (Mrs. French), Wisconsin (Baker), New York (Under- 

 wood), Connecticut (Miss White), and most of the other states 

 south to North Carolina and west to California. 



2. Elfvingia fasciata (Sw.) 



Boletus fasciatus Sw. Prod. 149. 1788; Y\. Ind. Occ. 3: 

 1 92 1. 1806. 



Polyporus fasciatus Yx. Syst. I : 373. 1821. 



