19] 5 



OVERHOLTS STUDIES IN THE POLYPORACEAE 683 



his valuable herbarium ; to Dr. B. M. Duggar for his interest 

 in the work and for aid in various ways; to the Missouri 

 Botanical Garden for the use of the herbarium material and 

 library facilities ; to Mr. C. G. Lloyd of Cincinnati, Ohio, for 

 aid iju determining some of the snecies. 



POLYPORUS ABIETINUS DlCKS. EX FRIES AND P. PARGAMENUS 



Fries 



P. abietinus was first described by Dickson, 1 in 1793, and 

 appears to be almost cosmopolitan in its distribution. In the 

 United States it is found wherever coniferous forests abound, 

 fr~;,i Canada to the Gulf of Mexico, and from the Atlantic to 

 the Pacific Ocean. It is never found on the wood of decidu- 

 ous trees, and as will be pointed out later, this fact affords 

 almost the only constant character by means of which it can 

 be separated from its near relative, P. pargamenus. 



P. pargamenus was described by Fries, 2 in 1838, from plants 

 ted on pine wood in Arctic America by the Franklin Ex- 



The plant has not been reported from the western 

 coast of the United States, but has been found in practically 

 every state east of the Mississippi Eiver, ranging west as far 

 as Wisconsin, Kansas, Arkansas, and Colorado. It is also 

 found in Europe. Most of the collections in this country 

 under the name P. laceratus Berk., P. xalapensis Berk., or 

 P. iHcincola Berk, and Curt., belong to this species. An ex- 

 amination of P. pseudopargamenus, as distributed by de- 

 Thuemen, 3 shows it to be identical with P. pargamenus. The 

 writer has not seen authentic specimens of the other species 

 named above, but they are given as synonyms by Murrill. 



By some writers the two species have been confused, due 

 to the fact that the type specimens of P. pargamenus were 



ted as growing on the wood of coniferous trees, while 

 in the United States the plant that has gone under the name 

 P. pargamenus is confined entirely to the wood of deciduous 

 trees. This has led some authors to regard the original P. 



1 PI. Crypt. Brit. 3: p. 21. 1793. 



2 Epicr. Syst. Myc. p. 480. 1838. 

 •Myc. Univ. 1102. 



