Murrill: Polyporaceae of North America 471 



surface smooth or tessellated, margin thin ; context thin, white, 

 fibrous, fleshy to tough, usually fragile when dry ; hymenium of 

 radiating rows of large, thin-walled, hexagonal tubes, usually 

 radially elongated ; spores smooth, hyaline. 



Species: H. alveolaris (DC.) Murr., H. micropora Mum, H. 

 daedalea (Link) Murr., H. Wilsonii Murr., H. hispidula (B. & C.) 

 Murr., H. princcps (B. & C.) Murr., H. fragilis Murr., H. flori- 

 dana Murr., H. tesscllatitla Murr., H. caper ata (Pat.) Murr., H. 

 brunneola (B. & C.) Murr., H. piirpuraseens (B. & C.) Murr., H. 

 portoricensis Murr., H. Jwndurensis Murr., H. indurata (Berk.) 

 Murr., H. cuctdlata (Mont.) Murr., H. Taxodii Murr. [See Bull. 

 Torrey Club 31 : 325-333- I 9Q4-] 



2. FAVOLUS Beauv. Fl. Owar. 1 : 1. pi. 1. 1805 



Type : Favolns hirtus Beauv. 

 Scenidium Kuntze, Rev. Gen. 515. 1893. Type: Favolus hirtus 

 Beauv. 



Hymenophore small, annual, epixylous, sessile, dimidiate or 

 reniform ; surface multizonate, margin thin ; context thin, leath- 

 ery, pallid or brown ; tubes alveolar; spores smooth, hyaline. 



Species : F. tenuis (Hook.) Murr., F. variegatus (Berk.) Murr. 

 [See Bull. Torrey Club 32: 99-103. 1905.] The first species 

 is usually white in substance, the other brown. 



3. Irpiciporus gen. nov. 

 Type : Irpex mollis B. & C. 



Hymenophore annual, epixylous, sessile, effused-reflexed, 

 white or pallid throughout ; surface anoderm, glabrous or velvety, 

 not distinctly zonate, margin acute ; context white, coriaceous or 

 corky ; hymenium hydnoid or irpiciform with traces of shallow 

 obsolete tubes near the margin ; spores smooth, hyaline. 



Synopsis of the North American species 



Teeth a centimeter or more in length ; pileus often large and thick. /. mollis. 

 Teeth one-half a centimeter or less in length ; pileus thin and shortly reflexed. 



/. Tulipiferae. 



Irpiciporus mollis (B. & C.) 

 Irpex mollis B. & C. Hook. Jour. Bot. I : 236. 1849. 

 Irpex crassus B. & C. Hook. Jour. Bot. I : 236. 1849. 



Described under the former name from Ravenel's collections 

 in South Carolina and under the latter lower down on the same 



