The Polyporaceae of North America.— V, The Genera Cryptoporus, 

 Piptoporus, Scutiger and Porodiscus 



By William Ali'honso Murrill 



The most important groups of the genus Fomes, as this term 

 is generally used, have been treated in the preceding papers of this 

 series. The plants heretofore considered are, for the most part, 

 perennial, with large stratified sporophores which grow conspicu- 

 ously upon the dead or dying wood infested by their very active 

 mycelium. The present paper deals chiefly with species found 

 under the genus Polyponis in Saccardo. These plants are annual 

 and their fruit-bodies are less conspicuous than those of the former 

 group, while their mycelium is usually comparatively limited in 

 extent. Most of the species here discussed are terrestrial and 

 somewhat fleshy, being allied to the Boletaceae. These terres- 

 trial species are exceedingly rare and beautiful in North America, 

 and present an interesting problem in distribution. The genus 

 Porodisais introduces the wood-loving forms of the genus Poly- 

 porus, which will form the subject of another article. 



Cryptoporus Shear, Bull. Torrey Club, 29: 450. 1902 

 The name Cryptoporus was first used by Peck (Bull. Torrey 

 Club, 7 : 104. 1880) to designate a new section of the Placodermei 

 made necessary by the discovery of a species of Polyporus having a 

 volva. His description of the section is as follows : 



" Pileus at first subcarnose, becoming harder or corky, sessile or 

 stipitate, the margins greatly prolonged beyond and beneath the 



[The preceding number of the Bulletin, Vol. 30, No. 7, for July, 1903 (30 : 369- 

 422), was issued lO Jl 1903.] 



423 



