1925] 



BURT THE THELEPHORACEAE OF NORTH AMERICA. XIV 295 



Missouri: Columbia, B. M. Duggar, 265, 288, IfiO, 472; Pacific, 



B. M. Duggar (in Mo. Bot. Gard. Herb., 63417); near St. 



Louis, E. A. Burt (in Mo. Bot. Gard. Herb., 63418). 

 Mexico: Tepeite Valley near Guernavaca, W. A. & E. L. Mur- 



rill, IfiO, comm. by N. Y. Bot. Gard. Herb, (in Mo. Bot. Gard. 



Herb., 54551). 



70. P. borealis (Peck) Burt, n. sp. 



Peniophora disciformis (DC) Cooke var. borealis Peck in 

 Harriman Alaska Exped. 5. The Fungi of Alaska, 43. 1904; 

 Sacc. Syll. Fung. 17: 175. 1905. 



Type: in Mo. Bot. Gard. Herb. 



Fructifications effused, thick, membranaceous, separable, be- 

 coming light buff in the herbarium, velvety with the numerous 

 cystidia, the margin thinner, entire, clay-color, free in some places; 

 in structure 60 y. thick, not colored, composed of hyaline hyphae 

 2 [i in diameter, not incrusted, densely and longitudinally ar- 

 ranged along the substratum and then curving obliquely out- 

 ward to form the hymenial layer, and of occasional slender gloeo- 

 cystidial organs with enlarged clavate or pyriform tips up to 

 43/2-7 \L in diameter; cystidia incrusted, cylindric, 60-75 X 6- 

 9 [i, confined to the hymenial surface but in great numbers there, 

 protruding nearly their whole length beyond the basidia; a single 

 detached spore is hyaline, even, 10 X 8 [x, but may be foreign. 



Fructifications 5 mm.-2J^ cm. long, 5 mm.-lO mm. wide. 



On bark of small decaying twigs of a frondose species perhaps 

 Alnus. Alaska. June. 



P. borealis has aspect somewhat suggestive of P. aurantiaca but 

 is more buff-colored, with darker margin becoming free, and with 

 cystidia so long and numerous as to be very conspicuous when 

 viewed with a lens. The abundance of these cystidia is so great 

 as to be a very important character in the recognition of this 

 species by preliminary inspection. 



Specimens examined: 

 Alaska : Aqua Dulce River, Yakutat Bay, W. Trelease, 583, type 



(in Mo. Bot. Gard. Herb., 5006). 



71. P. lepida Bresadola, Mycologia 17: 70. 1925. 

 Type: in Weir Herb. 





