298 ‘MurRILL: PoLYPORACEAE OF NORTH AMERICA 
1. Elfvingia fomentaria (L.) 
Boletus fomentarius L. Sp. Pl. 1176. 1753. 
Boletus ungulatus Bull. Herb. France, p/. ggz. fig. 2, C. D. £. 
Polyporus fomentarius Fr. Syst. 1: 374. 1821. 
Fomes fomentarius Gill. Champ. Fr. 1: 686. 1878; Icon. 
467. 
See also Sowerby, Engl. Fungi, f/, 733, and Schaeffer, p/. 
I37° 
This fungus is widely distributed on birch and beech in the 
temperate regions of Europe 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. fomentarius 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 Inzengae De Not., but as this does not occur 
in North America it need not be discussed at present. When 
fruit-bodies of P. fomentarius 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. nigricans Fr. 
At Kew, P. igniarius and P. applanatus have been variously con- 
fused with P. fomentarius. 
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; Fl. Ind. Occ. 3: 
1921. 1806, 
Polyporus fasciatus Fr, Syst. 1: 373. 1821. 
