276 GRASSES OF IOWA. 



Iowa. In Europe, Eriksson and Henning* have described the 

 above species. 



Puccinia graminis has also been reported on timothy in this 

 country. It is possible, however, that the Puccinia graminis 

 recorded may be the Puccinia phlei pratense. ^cidium unknown; 

 uredo sori perennial occur on the leaves and sheaths; confluent, 

 brownish yellow, 18-27 xl5-19 ". The elongated confluent, 

 brownish-black or black sori are open or exposed, or with par- 

 tially removed epidermis; contain the teleuto spores, which are 

 spindle or club-shaped, somewhat constricted in the middle; 

 chestnut brown, round or pointed; the apex strongly thickened, 

 38-52" X 14-16". From experiments made by the Swedish work- 

 ers it appears that this rust is in no way connected with the 

 barberry cluster cup fungus. 



Gama grass rust {Puccinia vexans, Parlow.) — This rust is 

 extremely common on Bouteloua racemosa. First described by 

 Professor Peckf from specimens collected by Brandegee under 

 the name of Uromyces brandegei (Peck). But the species was 

 first correctly determined as a Puccinia by Parlow.]; . He deter- 

 mined that there were two kinds of thick-walled spores with a 

 permanent pedicel; the two-celled being far more common in the 

 summer, while the one-celled produced during the fall. The 

 eecidium stage of this fungus is unknown. Uredo sori are pro- 

 duced on the upper surface of the leaf and occur in'small yel- 

 low spots. Spores oblong or elliptical, minutely roughened, 

 15-25" across sori, with numerous paraphyses. The one- celled 

 mesospores are globose to oblong. The exospore covered 

 with small papillao; spores 25-30" broad by 30-38" long. Apex 

 of the spores strongly thickened. Pedicels colorless, longer 

 than the spores; two-celled spores smooth. 



Blue stem rust. — Blue stem rust is rather common on tall blue 

 stem {Andropogon provincialis) as well as the little blue stem 

 {Andropogon scoparius); furthermore, it is common on other 

 species of the genus in southern United States. This species 

 was first described by Schweinitz. § Uredo sori brownish 

 orange on the under surface of the leaf, sometimes confluent. 

 Uredo spores sub-globose, 21-31" in diameter, roughened. 



*Dle getrelderoste. 153. 



tBot. Gaz. 4: 127. 



Saccardo. Syll. Fung. 7: 733. 



$Ellis. North Am. Fungi. 1051. 



INorth American Fungi. 295. 2911. 



