BULLETIN 



OF THE 



TORREY BOTANICAL CLUB. 



Vol. XVII.] New York, December 9, 1890. [No. 12. 



Notes on Corticium Oakesii, B. 6l C, and Michenera Artocreas, B. &. C, 



By George James Peirce. 



Plate ex. 



In the order Thelcphorcac there are many interesting species of 

 fungi, of which the greater number grow upon the bark of trees. 

 I w^ish to speak in this paper somewhat in detail of the structure 

 of the species first described by Berkeley and Curtis as Corticiunr. 

 Oakesii. 



ft 



In and upon the bark of certain species of Salix the mycelium 

 of Corticium Oakesii^ B. & C, spreads, forming at last a hymen- 

 ium which is nearly if not quite sessile. It is shaped like a flat 

 bowl, greyish or flesh colored, and consists of a margin of rather 

 closely compacted hypha2, and of the hymenial surface proper 

 which is composed of somewhat club-shaped basidia separated from 

 one another by hairs which are branches of ordinary hyphal 

 threads, and constitute true paraphyscs. 



The paraphyses, which are short and also somewhat club- 

 shaped, are thickly beset at their tips with short, bristle-like 

 processes (see figure a) upon which, at certain stages at least, 



w 



conidial spores may be borne. After the paraphyses have at- 

 tained to such a bristly developemcnt that they have the appear- 

 ance of test-tube brushes, some of them (see figure d) begin to 

 grow again at tlieir tips. Tliose threads which do not resume 

 their growth lengthwise become stouter and more abundantly 

 clothed with bristles than the others. The second growth is al- 



i 



ways separated from the first by a more or less pronounced con- 

 striction (see figs, d, e, f, g) in and below which, as would be 

 expected, the older bristles are found. The second growth is 



