182 IOWA ACADEMY OF SCIENCE Vol. XXVI, 1919 



Illinois, but with no evidence of P. graminis. The uredo and teleuto 

 pustules of the rust on the E. canadensis and E. robustus are some- 

 what scattered. Cultural experiments were not made, but I am told 

 by Mr. Kirby that some of this rust obtained by culture is un- 

 doubtedly P. graminis. It has, however, none of the external ap- 

 pearances of the P. graminis as it occurs on E. Macoiinii and Agro- 

 pyron repens and A. Smithii. The pustules of the rust on E. 

 robustus are not often confluent although the teleuto sori occur 

 around the stem sometimes for nearly the entire length of the 

 culm. The plants of Elymus canadensis and E. robustus with uredo 

 spore pustules appear to be P. graminis. These plants were invari- 

 ably near Agropyron tcnerum, A. Smithii and Hordeum jubatmn. 

 A Puccinia resembling Puccinia graminis was found in abundance 

 on Panicum virgatum near Camanche. It was growing in proximity 

 to Elymus robustus, but the wild rye was free from rust. The 

 Puccinia on Panicum virgatum is usually referred to P. Pammelii 

 whose aecidium stage occurs on Euphorbia corollata. This spurge 

 was common in the vicinity. Another rust, the Puccinia montanen- 

 sis Ell., first described on Elymus condcnsatiis Ell., occurs on the 

 leaf and was described as f ollo.ws -.^ "Sori mostly linear, lying be- 

 tween the nerves of the leaf and often confluent for 1 cm. or more 

 long, so very abundant as to blacken the leaf, hypophyllous, black, 

 at first covered by the epidermis, but soon bare, not prominent. 

 Teleutospores ovate or elliptical. 25-50 by 15-22 m, sessile or nearly 

 so, moderately constricted at the septum, apex rounded or flattened, 

 sometimes obliquely flattened, strongly thickened, but not papillate, 

 darker colored and mostly shorter and broader than in P. rubigo- 

 vera. The sori are mostly surrounded by paraphyses. The habit also 

 is different." It is a well known rust of Iowa on several species of 

 Elymus. H. H. Hume^*' described it because of the marked pecul- 

 iarities of the teleutospores. This rust has been found repeatedly by 

 me during the past summer on Elymus canadensis, E. robustus and 

 E. virginicus. H. S. Jackson in the Uredinales of Indiana reports 

 this rust (Diccroma montanensis) (Ell.) Kuntze on Elymus cana- 

 densis. The writer and Miss King" in 1912 referred a leaf rust 

 found on Phleum pratense and Elymus robustus to Puccinia hnpa- 

 tientis (Schw) Arthur. This was' based on the work done by Arthur 

 in 1902^-. Only a single species of grass was there recorded. 



9 Journal Myc. 7 : 2 74. 



i"Bot. Gazette 2S : 4 29, f. 4, 1899. See also Saccardo Sylloge Fungorum 11 : 

 201. 



"Rep. Ind. Acad. Sci. 191. '5 : 454. 

 '-Bull. Ta. Agrl., Rxp. Sta. 131 : 204. 



