168 IOWA ACADEMY OF SCIENCE Vol. XXVI, 1919 



feet barley in only a few cases." The statement signifies that this 

 rust overwintered at St. Paul, Minnesota, in 1916-1917, a severe 

 winter. 



May not some of the inability to infect other grasses and the bar- 

 berry be due to the condition of the Darluca filuni which is a serious 

 parasite of this host? 



GRASSES ON WHICH PUCCINIA GRAMINIS OCCURS 



It may be of interest to briefly discuss the grasses on which the 

 various forms of Puccinia graminis have been found by investigators. 

 The reference to rust in all cases is merely to the species and not to 

 the biologic form. The grasses are distributed in the following 

 tribes; PHALARIDE^: Phalaris canariensis, AntJioxanthiim 

 Puelii; AGROSTIDE^: Agrostis alba, Sporoholus cryptandrus, 

 Calmagrostis canadensis, Phleum pratense, Alopecurus pratensis, 

 A. genicnlatiis; AVEN^: Avena sativa, A. fatna, Holciis lanatus; 

 FESTUCE^ : Dactylis glomerata, Bromus sccalinus, B. hordea- 

 ceus, B. pumila, Koelcria cristata; HORDK^ '."Agropyron Smithii, 

 A. repens, A. tencriim, A. pseudorcpens, A. Richardsonii, A. deser- 

 toritm, A. cristatmn, A. elongatuin, Hordeum iiihatum,^H. ccespi- 

 tosum, H. pusillum, H. vulgar e, H. pammeli, Triticum vulgar e, Se- 

 cale cereale, Elynius Macounii, E. hracJiystachys, E. virginicus,^E. 

 glaucus. 



The following species — Agropyron dcsertormn, A. cristatmn and 

 A. elongatum — on which P. graminis has been reported by Stakman 

 and Piemeisel do not occur in the region and hence \\'\\\ not be dis- 

 cussed. 



Phalarideag 



Phalaris canariensis L. Canary grass is a naturalized plant in 

 Wisconsin, Iowa, Illinois and Minnesota. It is, however, not abund- 

 ant anywhere. I observed the plant in a few places, but no rust was 

 observed on it. The ribbon grass (PJuilaris arundinacea L.), which 

 is grown as an ornamental plant in some places was observed also at 

 Manchester, within a few feet of a barberry bush, but no rust was 

 observed on the grass anywhere in the region. It is common in the 

 swamps and lake region of northern Iowa and along the Missouri 

 river. In no case did I observe Puccinia graminis on it. Anthoxan- 

 thum Puelii L., sweet vernal grass, is not uncommon in lawn grass 

 mixtures, but I have not observed P. graminis on it. 



