[Vol. 2 



760 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



Fries, Elenchus Fung. 1 : 215. 1828. — Thelephora acerina 

 forma Abietis Fries, Syst. Myc. 1:453. 1821. — Corticium 

 Abietis (Fr.) Romell, Bot. Not. 1895:72. 1895.— Xerocarpus 

 farinellus Karsten, Finska Vet.-Soc. Bidrag 37 : 139. 1882. 



Illustrations: Bresadola, loc. cit.; Patouillard, Essai 

 Taxon. Hym. 25. /. 17b. 



Fructification effused, closely adnate, crustaceous, slightly 

 pulverulent, shining white at first, at length darkening in 

 the central portion from cartridge-buff to pale drab-gray, 

 cracked, the margin much thinner and farinaceous ; structure 



in section, 50-150 n thick, (1) with hyphae 

 next the substratum interwoven, 2 n thick, 

 the wall gelatinously modified, (2) hy- 

 menial layer 40-60 /x thick, composed of 

 basidia and of paraphyses branched at the 

 apex into very fine branches loaded with 

 Fi g- 3 minute granules ; basidia more abundant in 



raraphyses O x540. the lower portion of the hymenial layer, 



longitudinally septate, 14 X 9 n ; spores 

 colorless, simple, cylindric, curved, 8-12 X 4-5 /*. 



Fructifications 3-9 cm. long, 1-3 cm. broad. 



On bark and wood of dead branches of spruce, pine, hem- 

 lock, white cedar, oak, ash, elm, maple, and elder. Canada, 

 northern New England, and New York to Georgia, and in 

 Washington. March to January — perhaps throughout the year. 



As good distinctive macroscopic characters this species has : 

 chalky white color with central portions ashy; powdery sur- 

 face under a lens ; thinness on drying and margin still thinner, 

 so that it appears mealy under a lens rather than mem- 

 branous. The fine branches and granules at the tips of the 

 paraphyses show best in lactic acid preparations ; potassium 

 hydrate solution has a solvent action here. I have not been 

 able to study an authentic specimen of Thelephora calcea Pers. 

 and accept Bresadola's conclusion on this point. 



Specimens examined : 

 Exsiccati: Romell, Fungi Exs. Scand. 129. 

 Austria: G. Bresadola. 

 Sweden: L. Romell, 58, 59; Stockholm, L. Romell, Fungi Exs. 



