[Vol. 5 



196 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



Syst. Myc. 1 



453. 



^ill», 



Oregon: White Pine, J. R. Weir, 398 (in Mo. Bot. Gard. Herb., 



16266). 

 Jamaica: Cinchona, F. 8. Earle, 417, N. Y. Bot. Gard., Plants 



of Jamaica. 



9. A. acerinus (Pers.) v. Hohn. & Litsch. K. Akad. Wiss. 

 Wien Sitzungsber. 116 : 804. pi 2. /. 6. 1907 ; Bourd. & Galz. 

 Soc. Myc. Fr. Bui. 28 : 352. 1913. 



Corticium acerinum Persoon, Obs. Myc. 1 : 37. 1796; 

 Romell, Bot. Not. 1895 : 71. ISd^.—ThelepJwra acerina Per- 

 soon, Syn. Fung. 581. 1801; Myc. Eur. 1 : 152. 1822; Fries, 



1821; Hym. Eur. 648. lS74:.—Stereum 

 acerinum (Pers.) Fries, Epicr. 

 554. 1838; Sacc. Syll. Fung. 6 : 

 587. 1888. 



Fructifications scattered, re- 

 supinate, crustaceous, adnate, 

 thin, even, white, the margin 

 abrupt; in structure 45-80 n 

 thick, consisting of densely ar- 

 ranged, hyaline, thin-walled, 

 suberect hyphae about 2-3 /it in 

 diameter, heavily incrusted, 

 rising between the basidia to 

 the surface and terminating in a racemose manner with short, 

 slender branches, loaded with crystalline matter; basidia 

 clavate, 30-45X6 /x; spores hyaline, even, 10-12x6-7 y.. 



Fructifications about 3 mm. in diameter, rarely elongated 

 up to 10 mm. long, 3 mm. broad. 



On bark of trunks of living maple, oak, etc. Vermont to 

 Texas, westward to Missouri, and in Cuba and Mexico. 

 Throughout the year. 



This species may be recognized by its occurrence in scat- 

 tered, small, white, circular or oblong fructifications on the 

 bark of trunks of living white oak, maple, elm, ash, etc. The 

 smaller spores, racemose paraphyses, and absence of gloeo- 

 cystidia are structural characters separating the species from 

 A. seriatus and A. nivosus. Our American collections are 



Fig. 9 

 A. acerinus. 

 Vertical section of fructification 

 showing scattered immature basidia 

 and absence of gloeocystidia, X92; 

 granule-bearing paraphyses aft«r re- 

 moval of the granular matter by 

 HCl. X870. 



