244 



GRASSES OP IOWA. 



dantly on one of the 

 best of our native spe- 

 cies of Bromus, the B. 

 breviari status and it has 

 been reported on B. cili- 

 atus by Dr. Halsted.* 

 It affects the inflores- 

 cence so as to com- 

 pletely destroy it. This 

 smut will probably not 

 occasion much loss, as 

 it attacks the inflores- 

 cence and the grass can be cut 

 before it appears, but it greatly 

 injures its vitality. 



The Ustilago jjer^ennans iu com- 

 on ArrhenatJieruvi avenaceuni; it 

 is, in fact, much more common 

 than the Brome smut and seems to be 

 the same as has been found by Professor 

 Tracy in Mississippi on the same host, and 

 called Cintractia avenew, Ellis and Tracy, f 

 and the I'stilago segetum of some writers 

 described long ago by Bulliard.|: The 

 correct combination Csti/ngo segefum (Bull.) 

 Dittm.g was made much later. The writer || 

 incorrectly referred the Iowa smut to Cin- 

 tractia aveneu'*. The affected plants are 

 pale in color and somewhat drawn out 

 The panicle is very light in color and is 

 readily distinguished from surrounding 

 healthy plants. The ovary is converted 

 into a compact brown mass made up of a 

 large number of small &ub-globose spores 

 which measure 5-6" in diameter. 



♦Bull. Iowa Agrl. CoU. 1886:59. Saccardo. Syll. Fung 

 Fig. 117. Porcupine grass 7:"161. Wlnler Die Pilze 1: 77. 

 +Jour. of Myc. 6: 77. 

 *Hls. Des Uhamp. Fr. 1 : 90 pi. 474. 

 §Dlttm. in Sturm Deutsch Fl. 3: 6". pJ. 33. 

 II Jour. Myc. 7:198. 



HKostrup Ustilagineaa danite 139 named the fungus I', percnnan)'. See Tubtuf 

 PflanzeDkrankbeiten. '.^99. 



smut (rstUaw hupadytes) 

 affecting parts of inflores- 

 cence and culm; a, spores. 

 King. 



