Jackson : New Rusts on Carduaceae 



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Micropuccinia conferta Arth. & Jackson ; Arth. Bull. Torrey Club 

 48 : 40. 1 92 1\ 



Micropuccinia Millefolii Arth. & Jackson ; Arth. Bull. Torrey Club 

 48: 41. 1921. 



Puccinia Emiliae P. Henn. Hedwigia 37: 278. 1898 



Puccinia Emiliae, a typical micro -Puccinia, is based on a collec- 

 tion made by Dr. J. Urban in Jamaica on Emilia sagittata (Vahl) 

 DC. It is also known on E. sonchifolia (L.) DC. and N eurolaena 

 lobata (L.) R. Br., having a distribution from southern Florida, 

 Panama, and the West Indies. 



In 1907, Rev. J. M. Bates collected at Red Cloud, Nebraska, a 

 short-cycled Puccinia on the cultivated Calendula officinalis L. and 

 Dimorphotheca cuneata DC. This rust has since been collected on 

 the former host at Guanabaroa, Cuba, by J. R. Johnston ; Urbana, 

 Illinois, by H. W. Anderson, and at New Castle, Indiana, by H. F. 

 Dietz. The last collection was found on plants grown in the green- 

 house, the others being garden collections. The rust had been 

 tentatively assigned to Puccinia recedens Syd. in the Arthur Her- 

 barium and the collection on Dimorphotheca was issued under that 

 name in Bartholomew's North American Uredinales 1863. 



Recently, while studying the short-cycled Puccinias of this 

 group, the writer found that, while there was some variation in the 

 collections on different hosts, there was no sharp distinction be- 

 tween P. Emiliae and P. recedens. The latter has slightly shorter 

 spores with somewhat thicker walls than the former. 



Puccinia recedens, however, is a northern rust occurring on 

 Senecio species and having a range extending from southern New 

 York to West Virginia along the Atlantic coast and across the 

 continent to the mountains of Oregon and Alberta. This species 

 is interpreted, on account of the morphology of the teliospores and 

 host relationships, as a correlated species with Puccinia (Dicaeoma) 

 Eriophorii Thitm., which has aecia on Senecio and telia on Erio- 

 phorum with a quite similar range in North America. 



Puccinia Emiliae, on the other hand, is apparently native of sub- 

 tropical regions. For these reasons it has been decided to keep 

 the two species separate and to assign to P. Emiliae the collections 



