[Vor. 5 
326 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
to 50 yw, originating from all parts of the setigerous layer al- 
though chiefly from the dark, subhymenial zone; spores hya- 
line, even, curved, 5-6x11-2 и, as seen in preparation of 
sections. 
Reflexed portion 3-7 mm. long, 10-15 mm. broad, often lat- 
erally confluent; resupinate portions up to 3x30 cm. and 
more. 
On dead limbs, usually of frondose species. Canada to 
Mexico, Maine to the Pacific coast, Alaska to California. 
Common in the north, rare further south. Throughout the 
year. 
H. tabacina is the commonest species of its genus in the 
northern United States and may be recognized by its reflexed 
fructifications tobacco-colored with bright golden yellow 
margin and intermediate layer, and by having the hymenium 
deeply cracked in resupinate portions into radiating systems, 
one system for about each centimeter of area. The specimen 
under the name Stereum avellanum from Fries in Kew Herb. 
is the old glabrous, somewhat reddish stage of H. tabacina; 
this specimen has led to the transfer of Sterewm avellanum 
to Hymenochaete by British authors and Saccardo. An older 
specimen of Thelephora avellana in Herb. Fries collected by 
E. Fries at Femsjo is not distinct from Stereum glaucescens 
but is unfortunately on coniferous wood, while, 7. avellana 
was published as occurring on Corylus, a frequent substratum 
in Europe for H. tabacina. The type of Thelephora im- 
bricatula in Herb. Schweinitz is a mixture of Hymenochaete 
tabacina, mounted on the right of the card, and of H. cor- 
rugata, mounted at the left. Both these species are present 
in the sample of T. imbricatula in Curtis Herb. but their order 
has been reversed in mounting. The portion of the original 
deseription pertaining to characters of reflexed portions of 
the fructifications is obviously based upon the H. tabacina 
portion of the type. Since Léveillé's transfer of T. imbrica- 
tula to Hymenochaete was probably based upon an authentie 
specimen from Schweinitz in Museum of Paris Herb., in 1846, 
this specimen will probably show whether any of H. corrugata 
