[Vol. 2 



718 ANNALS OP THE MISSOURI BOTANICAL GARDEN 



The characters cited above do not appear to the writer to 

 be sufficient to warrant the complete separation of the two 

 species. They are sufficiently distinct, however, to enable one 

 to refer to one form or the other all the specimens collected. 

 It has been thought best to refer F. nigricans as a variety of 

 F. igniarius. 



The following diagnosis of the species and its variety is 

 appended : 



1. Fomes igniarius Linn, ex Fries. 



Typical form: Pileus convex or ungulate, 3-10 X 5-20 X 

 2-10 cm., grayish black or black, rarely roughly rimose with 

 age, not incrusted ; context hard and woody, brown, 0.5-1 cm. 

 thick; tubes 2-5 mm. long each season, the older layers con- 

 spicuously white-stuffed or incrusted, the mouths brown, 

 averaging 4-5 per mm. ; spores globose or subglobose, smooth, 

 hyaline, 4^6 /x; setae present though sometimes rare, sharp- 

 pointed, 16-25 X 6-8 /*; hyphae 3-4 n. 



Var. nigricans Fries : Pileus plane to convex, 3-10 X 

 3-15 X 2-7 cm., black, sometimes shining black, the surface 

 often cracked in both directions but never roughly rimose; 

 context and tubes as in the typical form, decidedly white in- 

 crusted; spores, setae, and hyphae as above, the setae often 

 abundant. 



On trunks of living deciduous trees. 



Illustrations: Published illustrations passing under the 

 name of this species and its variety are abundant, but typical 

 representations of my plants so referred are scarce. The type 

 form intergrades into the variety to such an extent that some 

 illustrations are hard to refer. The typical form is repre- 

 sented by Hard, Mushrooms, /. 349, and in pi. 25. f. 18. of 

 this paper. The variety is well represented by Lloyd, Myc. 

 Notes 29 : /. 193; Rostkovius in Sturm's Deutsch. Fl. 3:fasc. 17. 

 pi. 51. 



Specimens examined 1 : Ell. & Ev. N. Am. Fung. 915 (Ken- 

 tucky). — Krieg. Fung. Sax. 526. — Thuem. Myc. Univ. 105. 

 Mo. Bot. Gard. Herb. 4037* (New York), 4043* (New York), 



1 Collections assigned to var. nigricans are marked with an asterisk. 



