IFrom the Bulletin of the Tokkey BoTANH ai. Cli'B, 3 1 : 325-348 June, 1904.I 



The Polyporaceae of North America — VII. The genera Hexagona, 

 Grifola, Romellia, Coltricia and Coltriciella 



William Alphonso Murrill 



In the last article of this series (Bull. Torrey Club, 31 : 29-44. 

 1904), the tough, wood-loving, central -stemmed polypores were 

 discussed under the genus Polyporus. The genus Hexagona is in 

 general readily distinguished from Polyporus by its lateral stem and 

 peculiar pores, but the two genera approach very near to one 

 another in some of their forms. Species of Grifola are large, 

 fleshy to tough and much branched, usually growing at the bases 

 of trees or arising from buried wood. The genera Romellia, 

 Coltricia and Coltriciella, although belonging to the brown -fleshed 

 section, are conveniently introduced here because their species are 

 stipitate and are ordinarily associated with the stipitate forms 

 already discussed. This latter group, moreover, is indirectly 

 related to Grifola through the genus Romellia, with its hyaline 

 spores, large, irregular pileus and thick, rather fleshy substance. 



HEXAGONA Poll. PI. Nov. 35.//. 2,3. 1816. 



This genus was founded upon Hexagona Mori. The genus 

 Favolus was based on Favolus hirtus. Both genera are monotypic 

 in origin. Unfortunately the two were interchanged by Fries, who 

 was unfamiliar with the species, and they have been improperly 

 used ever since. In the Systema, Fries followed Beauvais and 

 included Hexagona under the subgenus Favolus of Polyporus. In 

 the Epicrisis, Fries includes F. hirtus, Beauvais' type, in the genus 

 Hexagona and follows it with H. Mori, Pollini's type. He then 

 begins his genus Favolus with F. europaeus, a synonym of H. Mori. 



The genus Hexagona comprises species with radially elongated 

 pores having normally six angles. In some species, the usual 

 form of the pores is not so evident, but general appearance and 

 habit serve to indicate generic limits. The line of demarcation 

 between this genus and Polyporus is difficult to draw. Most of 

 the species of Hexagona are laterally stipitate or almost sessile, but 



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