132 



Mycologia 



July II. Hordcitm jnhatiim showed a slight infection, uredinia 

 appearing on July 3, but telia were not formed, the plants not 

 being healthy. There was no infection of the other grasses. On 

 June 24, Bromtis ciliatus was inoculated and uredinia were 

 noticed on July 3 and telia by July 8, both were produced in great 

 abundance. 



Examination showed the rust on Bromits, both the field and 

 culture collections, to possess teliospores very variable in size, 

 shape and number of cells, only rarely could two-celled spores of 

 the Puccinia type be found, practically all of the spores being 

 three to several celled, some having as many as sixteen cells. The 

 teliospores on Elymiis were typical of Puccinia Agropyri, both 

 those developed from the culture and field collections, though a 

 few were three or more celled. 



As Long (Jour. Agr. Res. 2 : 303. 1914) has shown that the 

 host plant afifects the morphological character of the spores in 

 Puccinia Ellisiana Thuem. it was thought possible that the rust 

 on Bromiis and Elymits might be identical though showing such 

 marked morphological differences in the teliospores. To test this, 

 inoculations were made with the urediniospores from the culture 

 on Bromus ciliatus on the following grasses : Elymus virginicus 

 L., Agropyron tencrum Vasey, A. Smithii Rydb., A. repens (L.) 

 Beauv. and Hordeum juhatum L. There was no infection of any 

 of the grasses so it seems probable that the form of Bromus is 

 biologically distinct, and that the plants of Thalictrum used in the 

 culture bore two kinds or strains of aecia, one capable of infect- 

 ing Bromus and another which infected Elymus, Agropyron and 

 Hordeum. 



Trelease (Jour. Mycol. i : 14. 1885) described a subepidermal 

 rust on Bromus as Puccinia tomipara Trel. on account of some 

 of the teliospores being three to several celled. Lagerheim placed 

 this species in the genus Rostrupia on account of the several 

 celled teliospores. Arthur (Mycol. 7: 74. 191 5) regards the 

 group of subepidermal forms passing under various names with 

 telia chiefly on Agropyron, Elymus and Bromus and aecia on 

 Ranunculaceous hosts as forming one species. This includes 

 Puccinia tomipara Trel. 



