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 Heragona 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. Pl. Nov. 35. pl. 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 
fexagona and follows it with H. Mori, Pollini’s type. He then 
begins his genus Favolus with F. europaeus, a synonym of H. Mort. 
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 Folyporus is difficult to draw. Most of 
the species of Hexagona are laterally stipitate or almost sessile, but 
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