1920] 



BURT — THELEPHORACEAE OF NORTH AMERICA. XII 181 



arranged, dark-colored, thick-walled, stiff hyphae 3|-4| ^x in 

 diameter, not incrusted, which give their color to the fructifica- 

 tion; no colored conducting organs, gloeocystidia, nor cystidia; 

 spores hyaline, 9X4 /x. 



According to the original collection of S. crassum in Herb. 

 Fries, this is a very distinct species, characterized by very dark 

 color throughout and by absence of colored conducting organs, 

 cystidia, and gloeocystidia. It is probably of local distribution, 

 for I have seen but one collection which is even doubtfully 

 referable to S. crassum. This specimen, collected at Motzo- 

 rongo, is wholly resupinate, with hyphae dark-colored and 

 ascending obliquely from the substratum instead of running 

 longitudinally, and the hymenium has dried pinkish buff. 



Specimens examined: 

 Mexico: Mirador, Liebman, type (in Herb. Fries); Motzorongo, 

 near Cordoba, W. A. & E. L. Murrill, 985 (in N. Y. Bot. 

 Gard. Herb, and Mo. Bot. Gard. Herb., 54648). 



53. S. radiatum Peck, Buffalo Soc. Nat. Hist. Bui. i : 62. 

 1873; N. Y. State Mus. Kept. 26:72. 1874; Sacc. Syll. 

 Fung. 6: 571. 1888; Massee, Linn. Soc. Bot. Jour. 27: 195. 

 1890. Plate 5, fig. 53. 



S. radiatum var. reflexum Peck, N. Y. State Mus. Rept. 

 49:45. 1896; Sacc. Syll. Fung. 14: 217. 1900.— An Thele- 

 phora (Stereum) corrugata Leveille, Ann. Sci. Nat. Bot. III. 

 5:150. 1846? 



Type: in N. Y. State Mus. Herb. 



Fructification coriaceous, resupinate, with the margin free all 

 around, sometimes reflexed on the upper side, the reflexed por- 

 tion becoming black above, velutinous, 

 crisped, and somewhat lobed; hymenium ^ 



uneven, not polished, marked with thick •^^ C\~ 

 ridges radiating from the center, Sudan- ^ 



brown, rarely black when turned upward Yig. 26. S. radiatum. 

 and exposed to direct sunlight and weather; Spores x 665. 



in structure 1000 /x thick, composed of 

 densely and longitudinally arranged, colored hyphae 3^-4 /x in 

 diameter, whose color is dissolved by dilute potassium hydrate 

 solution; no cystidia; spores from spore collections white, 

 even, slightly curved, 9-10X3^-4 fx. 



