1918] 



BURT THELEPHORACEAE OF NORTH AMERICA. X 



349 



Fig. 19 



H. spreta. 



Section X44. From type. 



stratose, composed of 1-3, or rarely up to 5, pairs of setig- 

 erous and hyphal layers, with the setigerous layers very dense, 

 about 45-200 /x thick, exceeding the alternating hyphal layers 

 which are composed of loosely inter- 

 woven, thick-walled, colored, even 

 hyphae 3 /z in diameter; setae numer- 

 ous, slender, subfalcate, 60-75x6 /x, 

 originating at all levels in each setig- 

 erous layer, protruding up to 50 ^; 

 spores hyaline, even, 4^x2^ ii. 



Fructifications 4-25x2-10 cm. 



Usually on decaying wood of fron- 

 dose species, rarely on coniferous 

 wood. Canada to Alabama and west- 

 ward to Washington, California, and 

 British Columbia. April to January. Common. 



The stratose structure of well-developed fructifications of 

 H. spreta locates this species in a small group of three species, 

 of which the others are H. digitata and H. cinnamomea, from 

 both of which thick fructifications of H, spreta may be sep- 

 arated readily by being deeply cracked and having setigerous 

 layers from 45-150 /x, or rarely more, in thickness, very com- 

 pact, and exceeding in thickness the adjoining, loosely inter- 

 woven hyphal layers. Fructifications of H. spreta in its first- 

 stratum stage, consisting of but one hyphal layer and one 

 setigerous layer, are frequently not cracked but have the 

 setigerous layer 45 ji or more thick and thicker than the hyphal 

 layer. 



Specimens examined: 

 Exsiccati: Ell. & Ev., N. Am. 'Fungi, 1936, 3304 the latter 



under the name Hymenochaete unicolor; Ell. & Ev., Fungi 



Col., 806, under the name H, unicolor. 

 Canada : Comox, Van Island, J, Macoun, 18, 

 Prince Edward 's Island : J. Macoun, 344. 

 Ontario: London, J. Dearness; Ottawa, J. Macoun, 6. 

 New Hampshire : Chocorua, W, G. Farlow, two collections, one 



of which (in Mo. Bot. Gard. Herb., 55258). 

 Vermont: Middlebury, C, G. Lloyd, 10671 (in Lloyd Herb., 



