20 



INVESTIGATIONS OF BUSTS. 



there exists a similar hardiness of the urcdo, of which cases the fol- 

 lowing- will be discussed here: 



Uredo of Kentucky Bluegrass Rust {Puccmia poariim Niels.). 



The writer has known for some time that the uredo stage of the blue- 

 grass rust is able to pass the winter alive and in g-erminating condition 

 during- any season as far north as Lincoln, Nebr., but additional evi- 

 dence has been obtained from time to time. At the same time it is sii^- 

 niticant that there is no record that the teleutospores have ever been 

 found, except in one instance, at the above-named place. In fact, few, 

 if any, uredoforms so hardy as this one exist in this country. On 

 February 1, 1893, this uredo was still alive in the vicinity of Man- 

 hattan, kans. Every month of the year it exists alive and growing in 

 great abundance everywhere about Washington, D. C. On March 2, 

 1898, it was found fresh on green leaves of the host at Lincoln, Nebr. 

 On the same spot of ground it was still growing and spreading rapidly 

 on May 8 of the same year. Host plants were transplanted that day 

 into a greenhouse, where the rust continued to increase rapidly. As 

 would now be supposed, the rust is sharply limited to its one host, 

 Kentucky bluegrass. The results of the following cultures may be 

 given in evidence. 



Table IV. — CuHure cxperimeitls (dlh the lurdo af Kenlurhj bluegrass. 



Uredo of Puccinia montanexsis Ell. 



This is, in some respects, one of the most interesting of grass rusts. 

 It is one of the " covered rusts," and is, indeed, so far covered that it 

 is often entire!}^ overlooked by collectors. The uredosori are very 

 uniform in size and are exceedingly small, it being necessary often to 

 examine them, or even find them, with a hand lens. They are ellip- 

 tical in shape and placed end to end in long, narrow, yellow strite 

 between the veins of the leaf. The teleuto stage is so far hidden as 

 to be detected only by a faintly darker color beneath the leaf epi- 

 dermis. The rust is the most nearly like P. glwnarum Eriks. and 



