[Vol. 5 



194 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



terminate, adnate ; in structure 200-250 n thick, not stratose, 

 composed of erect, interwoven, thin-walled, hyaline hyphae 

 about 2 /x in diameter, bearing a large amount of incrusting 

 granular matter; hymenium consisting of basidia, gloeo- 

 cystidia, paraphyses, and many incrusted hyphae; gloeo- 



cystidia clavate, hya- 

 line, even, 18-30x9 m; 

 paraphyses about 2-3 n 

 in diameter under the 

 incrustation, cylindric, 

 flexuous, more or less 

 irregular in form, some- 

 what corymbosely 

 branched a t surface 

 of hymenium and 

 with branches loaded 

 with crystalline matter ; 

 basidia clavate, 40-60 X 

 12-16 n, only rarely 

 found, with 4 divergent 

 sterigmata ; spores hya- 

 line, even, 15-20x12- 

 16 IX. 



Fructifications 3-30 



mm. long, about 2-6 



mm. broad. 



On bark of living trees, common on Juniperus virginiana, 



occurs also on Juniperus occidentalis and Chamaecyparis. 



Vermont to Texas, westward to Oregon, and in Jamaica. 



Throughout the year. 



A. nivosus is intermediate between A. candidus and A. 

 acerinus, differing from the former by thinner and more 

 elongated fructifications which are not at all stratose within, 

 by incrusting matter not in the fonn of large, angular, crystal- 

 line grains, by margin with no tendency to be free nor black- 

 ening on under side, and by the common occurrence of the 

 fructification on bark of living red cedar. It differs from A. 

 acerinus by presence of gloeocystidia, which show best near 



Fig. 8. A. nivosus. Granule-bearing para- 

 physes, g, after removal of the granular matter 

 by HCl; gloeocystidia, gl; basidium, 6; spores, 

 s. X870. 



