1920] 



BURT THELEPHORACEAE OF NORTH AMERICA. XII 221 



Fructifications 5-10 mm. in diameter, becoming confluent 

 over areas 1-2 cm. wide and up to 12 cm. long, and reflexed 2-7 

 mm. 



On wood and in crevices of the bark of dead limbs and logs of 

 Eucalyptus, oak, pecan, and other frondose species. Oregon to 

 Mexico. September to April. 



Resupinate specimens of S. heterosporum are not distinguish- 

 able in aspect from the darkest colored specimens of S. alboba- 

 dium; all specimens of the former which have been seen so far 

 have been bister or seal-brown, which is also the color of the 

 upper side of the pileus. Mature specimens of S. hetero- 

 sporum differ from those of S. albobadium in the much thicker 

 zonate hymenium which has cystidia in all parts of this layer 

 and many wholly buried below the surface ; the deeper region of 

 the hymenium is dark-colored in the type because of the abun- 

 dance of dark-colored hyphal ends which are occasionally in- 

 crusted, and colored imbedded spores are as numerous as in 

 Stereum rugisporum, which has nearly the same geographic 

 range. I have not found colored imbedded spores in the collec- 

 tion distributed in Ell. & Ev., Fungi Col., 1116, which I refer to 

 S. heterosporum on account of other distinctive characters of this 

 species. 



Specimens examined: 

 Exsiccati: Ell. & Ev., Fungi Col., 1116, under the name Stereum 



albobadium. 

 Oregon: Portland, C. J. Humphrey, 6125. 

 California: Berkeley, C. J. Humphrey, 5981; Campo Mts., 

 C. R. Orcutt, 2007, 2008, comm. by U. S. Dept. Agr. Herb.; 

 Compton, A. J. McClatchie, in Ell. & Ev., Fungi Col., 1116, 

 and (in N. Y. Bot. Gard. Herb., Burt Herb., and Mo. Bot. 

 Gard. Herb., 56769); Claremont, D. L. Crawford, 1513, 

 comm. by L. 0. Overholts, 3325 (in Mo. Bot. Gard. Herb., 

 21688) ; Santa Cruz, Dr. Anderson, comm. by W. G. Farlow. 

 Arizona: Coronado National Forest, G. G. Hedgcock & W. H. 

 Long, comm. by C. G. Humphrey, 2562, 2563 (in Mo. Bot. 

 Gard. Herb., 13070, 12811). 

 Mexico: Parral, Chihuahua, E. 0. Matthews, 3, and 27, type 

 (in Mo. Bot. Gard. Herb., 44282, 44420, 44106); Rosario, 

 E. 0. Matthews (in Mo. Bot. Gard. Herb., 44110). 



