45 ^ 



March 1905] Cultures of Uredineae in 1904. Jffi. 



1 am under many obligations to a number of botanists, who 

 have most kindly sent me teleutosporic material, and in some cases 

 particular host plants on which sowings could be made. My espe- 

 cial thanks are extended to those who have made field observations, 

 and provided me with clues to solve the relationship of isolated 

 forms, the information received from Rev. J. M. Bates, and Mr. 

 E. W. D. Holway, being particularly helpful. Further acknowl- 

 edgments are made under the several species. I should further 

 mention the kindness of Messrs. R. Douglas' Sons, of Waukegan, 

 111., who sent twenty-five thrifty young larch without asking pay- 

 ment, as they did a year ago. 



During the present season 90 collections of material were 

 employed, and 261 drop cultures and 10 Petri dish cultures were 

 made from them to test the germinating condition of the spores. 

 Out of these 38 collections refused to germinate, and were conse- 

 quently useless. There were in all 264 sowings of spores made, 

 representing 40 species of rust, and for this purpose were required 

 119 species of hosts temporarily grown in pots in the greenhouse. 



A few cultures were made with material for which no clues 

 were obtainable to indicate the possible relationship, and in every 

 case with negative results. The record is given here, as in pre- 

 vious years, to serve for future reference. 



1. Puccinia on the leaves of Elymus Canadensis L., sent by 

 Rev. Bates from Red Cloud, Neb., was sown on Baptisia tinctoria, 

 Poly gala Senega, Uvularia perfoliate, Mi mid us ringens, Symph- 

 oricarpos pauciflorus, and S. racemosas, with no infection. Two 

 other hosts were tried in 1903, with equally negative results. 3 



2. Puccinia on Muhlenbergia Mexicana, sent by Mr. E. 

 Bartholomew from Stockton, Kans., was sown- on Hibiscus mili- 

 tariSj with no infection. Similar material sent by Rev. J. M. 

 Bates from Red Cloud, Neb., on M. racemosa, was sown on Ascle- 

 pias iucarnata, and twice on Hibiscus militaris, with no infection. 

 What is probably the same fungus on the. latter host coming from 

 Callaway, Neb., was sown: in 1902 on ten other species of hosts 

 with equally negative results. 4 It is evident that while some of 

 the rust found upon Muhlenbergia undoubtedly is associated with 

 the aecidium on Hibiscus, as Professor Kellerman clearly proved 

 last year, 5 there are other forms having entirely different aecidia, 

 not yet ascertained. 



3. Puccinia on Carex Pennsylvania, sent by Rev. Bates 

 from Red Cloud, Neb., was sown on Ambrosia triUda, Polemo- 

 nium reptans, Erigeron annuus, Lepidium apctalum, and Solidago 



'Jour. Mycol. 10:10. 1904. 



4 Bot. Gaz. 35:11. 1903. 



5 Jour. Mycol. 9:109, 232. 1903. 



