88 



Mycologia 



record of a smut on Ire sine or any of its near relatives could be 

 found in the host index of the Bureau of Plant Industry. 



According to Clinton's key in North American Flora, the smut 

 belongs in the genus Tolyposporium, but no species described by 

 Clinton fits the smut found on Iresine, which is therefore de- 

 scribed here as new. 



As southern Indiana approaches the northern limit of Iresine 

 paniculata, it was thought that the smut might be found in 

 Arkansas, where the plant is a very common weed. No speci- 

 mens of the smut could be found here, however, in the limited 

 search made during the past season, and so far the smut is known 

 only from the place where it was collected by Mr. Dean. 



Tolyposporium iresine sp. nov. 



Sori in ovaries, infecting all the ovaries of a flower, sparingly 

 scattered throughout the inflorescence, subglobose to globose, 1-5 

 mm. in diameter, covered with a gray-green, rather tough mem- 

 brane which on rupturing discloses the granular spore-mass ; 

 spore-balls olive-brown, translucent to nearly opaque, subspher- 

 ical to spherical, firm, composed of from 15-75 spores, 32-70^ in 

 length, mostly about 60 }x ; spores olive-brown, subspherical, lens- 

 shaped, to irregular depending on compression due to surround- 

 ing cells, adhering in a hollow ball by folds of their outer thick- 

 ened, rugose membrane, which may entirely separate from some 

 of the cells on rupturing, 12-20 /x in diameter. 



On Iresine paniculata, Posey County, Indiana. Collected by 

 Chas. C. Dean, Sept. 21, 1918. Flora of Indiana, No. 26, 651. 

 Known only from the type locality. 



University of Arkansas, 



Fayetteville, Arkansas. 



