1925] 



BURT — THE THELEPHORACEAE OF NORTH AMERICA. XIV 293 



Michigan: Marquette, C. J. Humphrey, 1870 (in Mo. Bot. Gard. 



Herb., 11089). 

 Wisconsin: Blue Mounds, E.T. & S. A. Harper, 895. 

 Washington: Bingen, W. N. Suksdorf, 741, 907. 



69. P. heterocystidia Burt, n. sp. 



TjT^e: in Burt Herb. 



Fructifications broadly effused, separable from the substratum 

 when moistened, becoming cracked in drying and often loosening 

 from substratum along the fissures, whitish when young, becoming 

 light drab, cinnamon drab or vinaceous drab, the margin often 

 paler; in section not colored or with only the hymenial layer 

 clay-colored or brownish, 200-400 [x thick, 2-layered, the layer 

 next to substratum usually broad, composed of loosely interwoven, 

 somewhat ascending or longitudinally arranged, hyaline, nodose- 

 septate hyphae 3-43/2 \^ i^i diameter, the hymenial layer 40-80 ^ 

 thick, composed of cystidia, gloeocystidia, and erect hyphae 

 usually slightly colored near plane of origin from the under layer; 

 cystidia consisting of both usual incrusted cystidia 25-35 X 

 6-8 [JL, distributed in all parts of the outer layer, and of very large 

 cystidia up to 40-100 X 20-50 [x which start from the base — 

 often somewhat colored — of the hymenial layer; gloeocystidia 

 slender, flexuous, 40-60 X 5-6 [x, between the basidia; basidia 

 with 4 sterigmata; spores from spore collection white, even, 

 cylindric, 12-15 X 3^-4^ P-. 



Fructifications 2-7 cm. in diameter. 



On fallen limbs of gray birch, beech, maple, Carpinus, Mag- 

 nolia, and other frondose species. Canada to Mississippi and 

 westward to Missouri and in Mexico. June to March. Com- 

 mon. 



P. heterocystidia resembles Corticium laeve Pers.( = C evolvens 

 Fr.) in color but is a true Peniophora, readily distinguished from 

 our other separable species by having incrusted cystidia of the 

 usual size, other very large cystidia up to 20-50 \l in diameter, 

 and gloeocystidia. Bresadola and von Hohnel & Litschauer con- 

 fused this species with P. carnea, from which it differs in being 

 much thicker, separable from the substratum when moistened, 

 and being colored within on the hymenial side instead of next 



