72 231 Mycologia 



years 14 to culture this rust, thirty-five species of hosts having 

 been used other than those used this year. Only once was a plant 

 of Viola used, V. striata, a caulescent species on which such 

 aecia have not yet been found, and are not very likely to occur. 



The successful cultures were inspired by field observations by 

 Dr. Brenckle, who sent us material with which to test his predic- 

 tion. In addition to Dr. Brenckle's opinion there was also at hand 

 the opinion of Mr. C. R. Orton, at that time working on the rusts 

 in my laboratory, which was drawn from a study of correlation 

 between this species and Uromyces pedatatus, in a paper read 

 December 28, 191 1, but not published until later, 15 the latter spe- 

 cies having its aecia on acaulescent violets. Since that time Mr. 

 W. H. Long has published 16 extended studies, both cultural and 

 morphological, with important bearings which can not be taken 

 into consideration in this connection. 



5. Puccinia Stipae Arth. Two collections with teliospores on 

 Stipa comata, gathered by Mr. E. Bethel, from different spots at 

 Boulder, Colo., were used for cultures. One was sown May 15 

 on Senecio lugens, S. spartioides, 17 Chrysopsis villosus, Grindelia 

 squarrosa, Gutierrezia Sarothrae, and Solidago mollis, all consid- 

 ered probable hosts for the aecia. Infection occurred only on 

 Gutierrezia Sarothrae, showing pycnia May 22, and aecia May 2J, 

 both in abundance. 



The other collection was sown May 17 on the same set of hosts 

 with infection only on Senecio spartioides, showing numerous 

 pycnia May 23, and aecia June 1. 



This species has previously been cultured 18 on Aster multiflorus, 

 A. ericoidcs, A. Novae-Angliae, Solidago canadensis, Grindelia 

 squarrosa, and Senecio lugens. The present study adds two 



14 See Jour. Myc. 14: 10. 1908; Mycol. 1: 231. 1909; 2: 220. 1910; and 

 4: 9. 1912. 



is Mycol. 4: 199, 200. pi. 70, figs. 5 and 6. 1912. 



i 6 Notes on three species of rusts on Andropogon, Phytopath. 2: 164-171. 

 August, 1912; and Influence of the host on the morphological characters of 

 Puccinia Ellisiana and Puccinia Andropogonis, Jour. Agric. Research 2 : 303- 

 319- July, 1914. 



17 The same host that was erroneously called 5". Douglasii in report for 

 1910. Mycol. 4: 9, 11. 1912. 



18 See Jour. Myc. 11: 63. 1905; and Mycol. 4: 19. 1912. 



