SPORES HYALINE. 





fragile. Pores small, round, drying slightly alutaceous. Spores allan- 

 toid, 1 x4-5, cylindrical, curved. 



This is the most abundant species we have in this section in the 

 United States, on birch usually. It occurs in Europe, but is very rare. 

 When fresh it has a slightly acrid odor. It accords very well with 

 Fries' account of Polyporus chioneus in Myc. Europ., and is so referred 

 by Karsten and Romell. However, it does not accord with description 

 of the original Polyporus chioneus, and the name having been applied 

 to different plants, we adopt Peck's name, which is the only certain 

 one. The surface is smooth, not "anoderm," but the crust is so thin, 

 a section under the microscope is necessary to clearly show it. It is 

 only about 50 mic. thick. Polyporus albellus is distinguished from 

 the plant we call Polyporus trabeus (cfr. page 301) only by its thin 

 crust. They are, no doubt, extreme forms of the same species. 



SPECIMENS. Many from United States. From Romell, Maire, and perhaps one or two others 

 from Europe. 



Compare acriculus, palustris. 



POLYPORUS PORTENTOSUS. Pileus usually large, 3-4 

 inches in diameter, 2-3 inches thick. Surface with a distinct, thin, pale 

 yellowish crust. Flesh pure white, fragile, chalky. Pores minute, 

 pure white. 



This is only known from Australia. It is a species quickly des- 

 troyed by insects, and the type at Kew is almost gone. We have the 

 only good collection known, which was from Geo. K. Hinsby, Aus- 

 tralia. A good account of this species is given in Cooke's Handbook. 

 As to context, it is quite close to Polyporus immaculatus, but readily 

 distinguished by its distinct crust. This is the largest, white Polyporus 

 known. It is recorded as large as ten inches in diameter. 



SPECIMENS. Australia, Geo. K. Hinsby. The only good collection in any museum. 



POLYPORUS TEPHRONOTUS. Pileus dimidiate, thin, 5-6 mm. Surface 

 smooth, with a thin, but distinct crust, slightly yellowish. Flesh white, soft, brittle. 

 Pores very minute, discolored slightly, with a waxy appearance. Spores not found 

 (allantoid?). This is only known from the type at Kew. There are several collec- 

 tions from Australia, and a large portion of them are semiresupinate. The pores 

 remind us much of those of Polyporus semisupinus. 



Compare angustus. 



POLYPORUS ELATINUS. Sessile, but attached by a reduced base (4 x 

 3x1 cm.). Surface with a thin but evident crust, smooth, wrinkled in drying, 

 reddish, ochraceous color. Flesh white, firm, 3-5 mm. thick. Pores small, round, 

 slightly discolored (now), with mouths darker, 6-8 mm. long. Spores abundant, 

 subglobose, hyaline, smooth, 6-7 mic., many smaller, 3-4 mic. Known at Kew 

 from good types, India. 



POLYPORUS ORINOCENSIS. Compare our Synopsis Hexagona, page 36. Has small 

 pores, but is so closely related to the large-pored species (Hexagona cucullata) that we figured it in 

 connection with that species. It is known from but one collection from South America, at Pans, 

 and is probably only a small-pored form of Hexagona cucullata. If ever found again, it might be 

 sought in this section of Polyporus. 



295 



