1915] 



BURr THELEPHORACEAE OF NORTH AMERICA. IV 641 



Exobasidium with 2-spored basidia and spores 16-20x8 /*. 

 The fungus agrees in all respects with the specimen in Briosi 

 and Cavara, 261. Several other collections on Vaccinium 

 membranaceum of buff colored leaf concavity and leaf spot 

 galls appear to bear Exobasidium Vaccinii. The very thick 

 spores, borne two to a basidium, distinguish E. Vaccinii 

 uliginosi from E. Vaccinii. 



3. E. Symploci Ell. & Mart. 



This fungus attacks the developing leaf buds of Symplocos 

 tinctoria and deforms them into a lobed mass. In fruiting, 

 the hyphae protrude on the surface of the mass and bear 

 acicular, simple, colorless, slightly curved conidia, ranging 

 from about 7X1 /* upward. The largest spores are 24x2 ju, 

 acicular, curved, and of the same form as those of inter- 

 mediate size and so on down to attached conidia. I have not 

 found any of the largest spores attached, nor have I found 

 basidia. In the original description the reference to spore 

 characters is " conidia hyaline, cylindric, nearly straight, 

 15-21X2 ix." 



I conclude that basidia have yet to be demonstrated for this 

 fungus. 



As I have had an opportunity to examine a large number 

 of Exobasidium specimens, collected in widely separated 

 localities, on many hosts and at various times in the growing 

 season, it has seemed that a concise summary of the data ob- 

 tained in regard to each specimen might prove useful for 

 comparison purposes to others who study our specimens of 

 this genus in the future. Pains have been taken to give the 

 hosts accurately. I am indebted to Dr. J. M. Greenman for 

 aid in host determinations in several cases. 



In the matter of spores the stated dimensions are those of 

 the preparations which were studied. No effort was made 

 to study preparation after preparation from the same collec- 

 tion in order to find spores possibly larger or smaller than 

 those of the first preparation which showed the spores well. 

 The dimensions stated are those obtained by treating all speci- 

 mens in exactly the same way and give such results as her- 

 barium specimens afford. 



