3 II MDC" 
1920] 
BURT—THELEPHORACEAE OF NORTH AMERICA. XII 151 
hymenium even, warm buff at first, sometimes becoming pale 
smoke-gray, unchanged when cut or bruised; in structure 
500-700 » thick under the hairy covering, with the inter- 
mediate layer bordered next to the hairy covering by a very 
dense, narrow, golden zone, the rest of the intermediate layer 
composed of densely and longitudinally arranged hyaline hyphae 
3-4 u in diameter, some of which in the subhymenium are thick- 
walled, up to 5-6 » in diameter, and very rarely have golden- 
brown contents as seen between the basidia; no colored con- 
ducting organs, cystidia, nor gloeocystidia; spores white in spore 
collection, even, flattened on one side, 5-73 X 2-21 u. 
Reflexed portion varying from barely reflexed up to 2 cm. 
broad, 1-2 em. long; fructifications merely gregarious or con- 
fluent, and imbricated. 
On logs and stumps of birch, beech, and other frondose 
species. Newfoundland to South Carolina and westward to 
British Columbia and California, and in Mexico. July to 
November in the east and to February in the Pacific states. 
Common. 
Stereum hirsutum is characterized by its strigose-hirsute, 
buff-colored pileus, weathering more or less gray, and by its 
warm buff hymenium, sometimes smoke-gray, which does not 
exude a red juice when wounded; as in S. rameale, S. versicolor, 
S. fasciatum, S. lobatum, S. australe, and S. gausapatum, the 
upper surface of the intermediate layer is differentiated into a 
thin, golden, somewhat horny crust from which the hairy cover- 
ing springs. This golden zone shows well under the microscope, 
and its presence is a decisive character for separating S. hir- 
sutum from the southern S. sulphuratum, a species of somewhat 
similar aspect. 
Specimens examined: 
Exsiccati: Berkeley, Brit. Fungi, 146; Cavara, Fungi Longo- 
bardiae, 61; Cooke, Fungi Brit., 108; Ellis, N. Am. Fungi, 
1204; Krieger, Fungi Sax., 118; Rabenhorst, Herb. Myc., 
211; Romell, Fungi Scand. Exs., 26. 
Sweden: Femsjó, L. Romell, two collections, and E. A. Burt; 
Mauritzberg, W. A. & E. L. Murrill, 4078 (in N. Y. Bot. 
Gard. Herb. and Mo. Bot. Gard. Herb., 56671); Stock- 
holm, L. Romell, 30, 401, and in Romell, Fungi Scand. 
Exs., 26. 
