Cultures of Uredineae in 1916 and 1917 



305 



with no infection, from material obtained by Prof. H. S. Jackson 

 in southern Indiana. Another collection secured by Dr. E. B. 

 Mains at Lafayette, Ind., was sown May 17 on E. corollata, and 

 again May 24, June 5 and 13, on E. Ipecacuanhae, with no in- 

 fection. In each case the teliospores showed fair germination and 

 the hosts were in excellent condition. Judging from morpho- 

 logical and host data these species of Euphorbia would be prob- 

 able aecial hosts, but all attempts at cultures 12 have so far failed. 

 I am indebted to Prof. J. B. S. Norton, botanist of the Maryland 

 Agricultural Experiment Station, for a number of serviceable 

 plants of E. Ipecacuanhae. 



3. Pucciniastrum Hydrangeae (B. & C.) Arth., on Hydran- 

 gea arborescens L., collected by Dr. E. B. Mains at Lafayette, 

 Ind., March 31, 1917, was sown May 12 on Tsuga canadensis, 

 Abies balsamea, Abies concolor, and Picea canadensis, with no 

 infection. Although no clues had been obtained from field ob- 

 servation, yet these genera of hosts include all on which any 

 species of Pucciniastrum has yet been grown, and the teliospores 

 were germinating freely, so there had been reasonable hopes of 

 success. 



Successful cultures in 1917 supplementing previous 

 work. — The successful attempts to connect the aecia on Iris versi- 

 color and on Rudbeckia laciniata with telial forms are the cul- 

 mination of efforts extending over several years, in which a num- 

 ber of persons have aided. Similar efforts to connect the local- 

 ized aecia on Houstonia caerulea and on Capnoides montanum 

 have so far been without success, that is, for this laboratory. 



1. Puccinia Majanthae (Schum.) Arth. — This year for the 

 first time American material of this widely distributed and highly 

 specialized rust has been cultured. The work was first done by 

 Prof. H. H. Whetzel at Ithaca, N. Y., in verification of observa- 

 tions at North Spencer, N. Y., made during the season of 191 6 by 

 Prof. Whetzel and Prof. H. S. Jackson. The account of the 

 work has not been published at the time of this writing. Both 

 before and after Prof. Whetzel had obtained his results he sent 



12 For previous attempts see Bot. Gaz. 35: 12. 1903; Jour. Myc. 8: 52. 

 1902; 10: 10. 1904; 12: 12. 1906; 13: 192. 1907; 14: 11. 1908; Mycol. 1: 

 230. 1909; 7: 65. 1915; and 8: 127. 1916. 



