SPORES HYALINE. SETAE PRESENT. 



difference in the color of the context of the two species. If Persoon or Fries met the 

 plant, they never noticed the difference. It is only recently that attention was 

 drawn to the fact that the plant on oak, called Fomes igniarius by the French bot- 

 anists to this day, is quite different from the plant on willow called Fomes igniarius 

 by Fries. Mr. Romell first brought it to my notice. Hartig (in 1878) figured under 

 the name Polyporus fulvus a Fomes on the silver fir (Abies pectinata). It has been 

 distributed from Italy as Fomes igniarius var. Abietinus. It was afterwards called 

 Fomes igniarius var. Pinuum and Fomes Hartigii. Notwithstanding the vastly 

 different host, it seems the same as Fomes robustus in all characters. I think Fomes 

 robustus is only known in Europe on oak and silver fir. In America the name does 

 not figure in our literature, being unknown to those who have worked here on the 

 subject. It is not known to me east of the Mississippi. A form (called Fomes 

 Bakeri) is said to be quite common on birch in Minnesota regions. From Texas 

 I have seen the type form of Europe on mesquite (and referred in error to Fomes 

 texanus). I have it from California, H. S. Fawcett, on Eucalyptus. 



The foreign specimens I have are from Australia, Hawaii, and Japan. A few 

 have setae and spores a shade larger (8-9 mic.), but otherwise are exactly the same 

 as the European form. Compare Fomes setulosus in Section 70, 



ILLUSTRATIONS. Hartig, Zersetz. d'Holzes t. 7, (as PoLyporus fulvus in error). In his 

 Diseases of Trees, this is referred to as Polyporus, Hartigii). 



SPECIMENS. Many from Europe, mostly from France, on oak; also from Alpine regions, 

 on the silver fir. I have seen none from England. From United States, only California. H. S. Fawcett, 

 on Eucalyptus; Hawaii, C. N. Forbes; Australia, A. G. Hamilton, on Eucalyptus; Japan, A. Yasuda. 



Forms. 



FOMES BAKERI is a form of Fomes robustus, very close in its bright rhei 

 context color, spores, etc. (6-7 mic. rather than 5 mic., as described), and which 

 differs only in its surface, which is smooth, subconcolorous, without the black, rimose 

 crust of the type. Museum specimens are only known to me from the originals in 

 Ellis' herbarium, and in my own, frpm C. F. Baker, Wisconsin. I am told by Prof. 

 Harper it is common on birch in Minnesota. 



NOTE. The plant distributed by C. F. Baker, No. 54, on Betula, Los Pinos, Colorado, and 

 determined by Underwood as Polyporus applanatus (sic), has same general appearance and surface 

 as Fomes Bakeri, but differs markedly in context color, and in having abundant setae. I should refer 

 it to Fomes pomaceus, although it differs slightly. 



FOMES SETULOSUS. Pileus ungulate, with a smooth, brown- 

 ish surface. Context fulvous (tawny of Ridgway), hard, woody, the 

 pore tissue a shade lighter than the context. Pores very minute, with 

 brown mouths. Pore layers 2-3 mm. wide. Spores globose, hyaline, 

 8 mic. Setae very abundant, with thick bases, and abruptly con- 

 tracted and slender points, projecting 12-14 mic. 



We base this name on species received from Ceylon, which are 

 close to Fomes robustus, and when received were referred as a setae- 

 bearing form of it. On comparing the context color, however, I find 

 it distinctly different, the difference shown in Ridgway's tawny and 

 yellow ochre on plate XV. In addition, it has quite peculiar and very 

 abundant setae, found but rarely, if at all, on the European plant. 

 There seems to be an intermediate plant in Australia closer to the 

 European plant. 



FOMES TORULOSUS. Pileus applanate, sometimes thin, an 

 inch or less thick; other specimens are 3-4 inches thick. Surface when 



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