1920] 



BURT — THELEPHORACEAE OF NORTH AMERICA. XII 129 



the general aspect and microscopic structure of specimens are 

 usually so similar to S. purpureum that it is distinguishable from 

 the latter only by the presence of weak flexuous hairs in the 

 hymenium which are not visible until sectional preparations are 

 examined with the compound microscope. Such hymenial hairs 

 were in 1839 figured by Berkeley, loc. cit., in illustrating the 

 hymenium of what he regarded as Thelephora purpurea but 

 which now appears to have been S. rugosiusculum. All speci- 

 mens in which these hair-like cystidia have been demonstrated 

 have been either resupinate or with simple, reflexed portion 

 not narrowly lobed or complicate. It has not been possible to 

 observe a specimen throughout its whole season of growth to 

 determine whether the hair-like cystidia are a constant character. 

 In forming the glabrous, rugulose surface upon which the specific 

 name is based, the specimens do not become denuded of their 

 original tomentose covering, for sectional preparations of such 

 specimens, mounted in liquid medium, show this hairy covering 

 to be of the original thickness and with the tips of the hairs no 

 longer adhering together into a plane surface but now floating 

 free. Probably the gluing together of the hairs into a glabrous 

 surface is a weather phenomenon. 



Specimens examined: 

 Exsiccati: Bartholomew, Fungi Col., 3489, under the name Ster- 



eum purpureum; Cavara, Fungi Longobardiae, 60, under 



the name Stereum purpureum; Ellis, N. Am. Fungi, 323, 



under the name Stereum purpureum. 

 Sweden: Stockholm, L. Romell, 33. 

 England: M. J. Berkeley, under the name Stereum vorticosum 



(in Kew Herb.). 

 France: Fautrey, determined by Patouillard as S. purpureum, 



comm. by Lloyd Herb., 4339, 4363. 

 Italy: F. Cavara, in Cavara, Fungi Longobardiae, 60. 

 Ontario: London, J. Dearness, in Bartholomew, Fungi Col., 



3489. 

 Maine: Morse, comm. by Sprague (in Curtis Herb., 5413, type 



of Stereum Micheneri as emended by Massee) ; Harrison, 



/. Blake, comm. by P. L. Picker; Piscataquis Co., W. A. 



Murrill, 1860, 2163 (in N. Y. Bot. Card. Herb, and Mo. 



Bot. Card. Herb., 56692, 56693). 



