26143 



Mycologia 



numerous, and bright orange-yellow, the latter are small, fewer 

 and nearly or quite colorless. Upon a careful examination of the 

 telial material used in the two successful trials, it is found that 

 while that from Kansas is the true Puccinia Muhlenbergiae, that 

 from Ohio is P. dochmia B. & C, or at least quite distinct from 

 the other. Considerable more study is needed to fully clear up 

 the relationship of the Muhlenbergia rusts. 



9. Gymnosporangium Libocedri (P. Henn.) Kern. For many 

 years the only known locality for the telia of this rust has been 

 in northern California at a place rarely visited by botanists. 

 While Mr. F. D. Kern during January, 1908, was working upon 

 material in the herbarium of Dr. W. G. Farlow at Harvard Uni- 

 versity, a collection of this rust was seen from Eugene, Ore., 

 made by Dr. A. R. Sweetser, of the University of Oregon. There 

 was also in the herbarium a collection, from the same locality 

 and by the same person, of Aecidium Blasdaleanum D. & H. on 

 Crataegus. This Aecidium has also been taken by more than one 

 collector from the region of the Libocedrus rust in California. 

 The Crataegus rust is stated by Dr. Dietel, in a note appended to 

 the original description, to be "a true Aecidium, and does not 

 belong to the genus Roestelia comprising the aecidial stages of 

 Gymnosporangium/' Recent very careful study confirms Dr. 

 Dietel's statement regarding its morphological resemblances, for 

 in the peridial cells, the spores, and the mode of dehiscence, which 

 provide the chief generic characters, it is wholly unlike the form 

 genus Roestelia. 



In order to secure culture material Dr. Sweetser was appealed 

 to. He responded promply with telial collections on Libocedrus 

 dccurrens, which came through the mails in perfectly fresh condi- 

 tion. For his efficient aid Dr. Sweetser is entitled to much credit. 

 A sowing was made April 1 on Crataegus Pringlei and Amelan- 

 chier canadensis, giving no infection on the Amelanchier, but on 

 the Crataegus numerous pycnia began to show April 12, followed 

 on April 20 by an abundance of well-formed aecia. Another 

 sowing was made on Crataegus sp. April 4, resulting in such a 

 heavy infection, the pycnia showing April 14, that the leaves were 

 killed before there was time for aecia to form. 



The aecia secured by the culture agree perfectly with Aecidium 



