22 



Mycologia 



above under nos. 3 and 4, and which have aecia on Aster, Solidago, 

 Euthamia, Erigeron, and close relatives. As the aecia and ure- 

 dinia of the two groups, one under the genus Puccinia and the 

 other under Uromyces, are indistinguishable, and as the telio- 

 spores of the Uromyces agree with the one-celled spores of the 

 Puccinia^ and also with the two-celled spores in all characters 

 except number of cells and consequent length, the former doubt- 

 less are morphological races of the latter. Relationship could be 

 shown better by putting all of these forms under one specific name, 

 and designating the several races by varietal names. But in the 

 present state of taxonomy of the rusts it is more convenient to 

 dispose of them under the two genera: Puccinia and Uromyces. 



The collection on Carex intumescens used in the culture is in 

 all respects identical with the type collection of Uromyces perigy- 

 nius, which was also on C. intumescens, but in the latter the large 

 green perigynia also bore sori as well as the leaves, which unusual 

 but incidental fact suggested the name. The similarity of this 

 species with the form having aecia on Solidago was pointed out in 

 1903,^^ but for precautionary reasons it was thought best at that 

 time to give the latter a separate name, U. Solidagini-Caricis Arth. 

 This name now becomes a synonym of the former, or may be used 

 to indicate the biological race with aecia on Solidago. The type 

 host of this form has been determined as C. deflexa, and not C. 

 varia as originally stated. 



It is further probable that the form on Carex scoparia bearing 

 the name U. caricina Peck, which often shows larger spores, 

 should be referred to U. perigywius, the last being the oldest name 

 of the three. A collection of this on C. scoparia was sent by Pro- 

 fessor Fraser, from Pictou, Nova Scotia, and sown on Lysimachia 

 terrestris, without infection. Its possible relation to the Aster- 

 Solidago group did not come to mind soon enough to put the mat- 

 ter to a test. 



22. Uromyces Junci (Desm.) Tub, on Juncus halticus Willd. 

 collected at Kulm, N. Dak., by Dr. J. F. Brenckle was sown April 

 14 on Carduus Flodmanii, Arnica sp., Grindelia squarrosa, Am- 

 brosia trifida, and Sidalcea oregana, with infection only upon the 

 first, showing pycnia April 29, and aecia May 4. Another sowing 



^'L. c. 



