GRASSES OF IOWA. 



245 



Fig. 118 Sprouting grass smut iUgtilago panici-miliacei) showing large swelling in 

 upper part of plant. (King.) 



Fig. 119. Tall meadow oat smat (Ustilago perennans). (King.) 



Birnyard grass is affected with several smuts which, by some 

 mycologists have been placed in the genus Ustilago. Burrili* 

 described aa Ustilago sphaerogena occurring in the ovaries of 

 barnyard grass. The pustulate swellings of the spikelet vary 

 greatly. The Burrill specimen is identical with Sorosporium 

 hullatum Schr.f or Tolyposporium bullatum Schr. The spore 

 masses are spherical or elongated, consisting of many spores. 

 The individual spores are somewhat polygonal, with a few 

 warty projections. This is true of the specimen collected by 

 Seymour in Osborn^, 111., and the Arthur specimen from 

 Ames. The writer has collected a somewhat similar fungus 

 with larger spores which are more minutely echinulate, in 



*Ellis and Everhart. N. \m. Fung. No. /SS:'. 



Saccardo Syll. Fung. 7: ■tt)8. 



Winter die Pilze. 1: 101. 

 tKrypt. Fl. Schles. 276. Saccardo Syll. Fung 7: 502. 



Bull. Torr. Bot. Olub. 22; 175. 



