GRASSES OP IOWA. 



241 



supposed to be identical with the smut occurring on wheat and 

 oats. 



The covered barley smut is said to be less abundant in 

 Denmark than the naked barley smut, but it is quite widely dis- 

 tributed in Europe. It is also widely distributed in the United 

 States: New Hampshire (Farlow), Maine (Harvey), Kansas 

 (Kellerman and Swingle), Michigan (Beal), Indiana (Bolley), 

 New York (Peck), and Iowa (Pammel, Stewart and Weaver). 

 It is more common in Iowa than naked smut. This smut was 

 first named by Persoon* and the correct 

 combination was made by Kellerman and 

 Swinglef who cite the very full literature. 

 This smut differs from all other loose smuts, 

 in that the panicle is not converted into a 

 loose powdery mass, but is more or less 

 covered by a membrane, which breaks and 

 allows the spores to be scattered through 

 the broken membranes. 



The spores of U. /^orcZei are dark colored, 

 spherical, slightly irregular, 5-8 x 5-7", 

 usually 6-8 x 7^ somewhat larger than U. 

 nuda. The exospore is smooth. Germina 

 tion proceeds readily in water with abun- 

 dant sporidia from which secondary spori- 

 dia occur. 



In naked barley smut the parts of the 

 floweriog panicle attacked are converted 

 into a loose powdery mass, thus allowing 

 the spores to be blown away very readily. 

 The membrane covering the smut is very 

 thin, dark, dull gray in color and easily 

 broken. It consists of the modified epider- 

 mal cells of its host; the whole of the 

 inflorescence being converted into a black- 

 ish powder. Kellerman and Swingle say: 

 ' ' The reason, notwithstanding the presence 

 of fibers and a thin enveloping membrane. 

 Fig. 116. coveredBar- this species Spreads its spores Very readily 



ley Smut (Usfi'tago /lordei). -. inT_a? jo , ■ -, 



(King) and seems wholly dinerent from typical 



*Syn. Meth. Fung. 224. 

 +Rep. Kansas Agrl. Coll, 1889: 268. 

 15 



