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 /x in diameter; setae numer- 

 ous, slender, subfalcate, 60-75x6 ju, 

 originating at all levels in each setig- 

 erous layer, protruding up to 50 /x; 

 spores hyaline, even, 4|x2| n. 



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 /x 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., 



