CONTEXT WHITE. 



FOMES ATRO-ALBUS (Fig. 574). Pileus small, about a cm. 

 in diameter, thin, applanate. Surface with a thin, black, zonate 

 crust. Context and pores white, contrasting with the 

 black surface. Pores minute, round. Spores (B) 

 2^x3x6-7 mic. 



This little species was well named from Java, 

 and is only known from this country. I have not 

 noted strata of pores and am not sure it is a Fomes. 

 There are specimens at Berlin and Kew. 



SECTION 58. CONTEXT PALE YELLOW. 



FOMES PINICOLA. Pileus applanate or ungulate. Surface 

 with a thin, resinous crust, at first white, soon reddish, finally black. 

 Context pale yellow, punky, but hard. Pores minute, round. Pore 

 layers about a cm. thick, pale yellow, harder than the context. Spores 

 3>^-4 x 7-10, obovate, hyaline, smooth. 



This is a most abundant species in all pine regions. It usually grows on acerose 

 wood, pine, hemlock, but is not rarely found also on birch and other frondose wood 

 in pine regions. Very common in the United States and Europe, and occurs no 

 doubt through the temperate world. We have seen specimens from Japan, Mexico, 

 India, Philippines, and (?) from New Zealand. There is no uniformity in regard to 

 the name, and in severaj museums it is found in three covers -Fomes marginatus, 

 Fomes ungulatus, and Fomes pinicola. Both Persoon and Fries thought that the 

 frondose wood from which they called marginatus was distinct from the pine woods 

 form. 



Dr. Harper and Prof. Peck both think that two different forms (or species) 

 occur. One an applanate, thin form with broad, annual layers, softer tissue and 

 short lived, the other ungulate, with many narrow, annual layers and long lived. 

 I am inclined to view the difference as one of nutrition. On some hosts (hemlock) 

 where the wood is softer and retains the moisture, the fungus makes a more rapid 

 growth, and more quickly extracts its supply of food, hence grows faster and does 

 not live so long. 



ILLUSTRATIONS. Schaeffer, t. 270 earliest and best. Gillet, t. 464 fine. Others are mostly 

 indifferent. 



SPECIMENS. Europe, many; United States, many; Japan, J. Umemura, A. Yasuda; Phil- 

 ippines, E. D. Merrill, (4 cols.); Mexico, Dr. M. M. Solorzano. 



Compare Alni, fulvus, helveolus, marginatus, ponderosus, ungulatus. 



FOMES SUBUNGULATUS. Described from the Philippines, is similar to 

 Fomes pinicola, and has been confused with pinicola. The context is isabelline 

 (rather than yellow) and softer. It has same crust, pores, and I think is an extreme 

 form of Fomes pinicola. 



FOMES LATISSIMUS. Pileus applanate. Surface with a 

 thick, rough, hard, black crust. Context hard, isabelline yellow. 

 Pores very minute, hard, more yellow than the context, indistinctly 

 stratose. Cystidia hyaline. Spores (B) 3>^-5 x 6-8. This is known 

 to me only from cotype specimen from Java. Murrill's reference to 

 Fomes ligneus from Philippines is said to be same thing. 



219 



