296 



Mycologia 



visited. This is the second culture and the second aecial field 

 collection so far secured. 



At Denver the writer was joined by Professor H. S. Jackson. 

 While here (May 26-31) we were under the guidance of Mr. 

 Ellsworth Bethel, whose extensive knowledge of the flora of 

 Colorado and especially his very intimate familiarity with the 

 rust flora of the foot hills and plains about Denver, together 

 with his highly enthusiastic and generous disposition, made the 

 days memorable for the number and important character of the 

 observations. Beside excursions immediately about Denver 

 longer trips were taken through the Municipal Mountain Parks, 

 to Pueblo, and to Boulder, all but the last by automobile with 

 observations along the way. The rust flora of this region is the 

 richest and most varied known to the writer, and the visit re- 

 sulted in a large increase in knowledge regarding new forms and 

 combinations. The identity of Puccinia Schedonnardi with P. 

 Muhlenbergiae } the status of Aecidium Abroniae, Aecidium Lia- 

 tridis and the aecia on Polygonum aviculare, heretofore errone- 

 ously associated with Uromyces Polygoni, were established, and 

 much else accomplished. A visit to Mr. Bethel's garden, in 

 which he carries out large numbers of open-air cultures, was most 

 instructive as well as indicative of the highly valuable character 

 of his studies. 



The final stop (June 1-2) of the journey was at Manhattan, 

 Kans., where over thirty years ago Professor W. A. Kellerman 

 brought to light a number of forms still imperfectly known. By 

 the aid of Mr. L. E. Melchers and other members of the Agri- 

 cultural College a fruitful reconnaissance of the vicinity was 

 made, resulting especially in detection of the alternate form for 

 the Aecidium on Allium, which had tentatively been assigned by 

 different observers to no less than four very unlike telial forms. 



Such excursions for observation as those just mentioned have 

 been of inestimable value in securing knowledge for the suc- 

 cessful prosecution of the culture work. Without numerous 

 cultures the marvelous advance of recent years in the taxonomic 

 study of American rusts would have been largely impossible. 

 Moreover, without the most varied cultures brought about by 

 observations in widely separated parts of the country the intricate 



