224 



Arthur: Cultures of Uredineae * 65 



sown April 17 on Lithospermum officinale, Aesculus glabra, Ele- 

 agnus argentea, Lepargyraea canadensis, and Doellingeria umbel- 

 lata. It was sown again March 20 on Sphaeralcea lobata, Calli- 

 rhoe digitata and C. involucrata. No infection was secured. 



This is the first attempted culture of this species with telio- 

 spores, although once grown from amphispores. 3 Most collec- 

 tions show only the amphisporic stage of the rust. No clue to the 

 alternate host has yet been obtained. 



3. Puccinia emaculata Schw. This exceedingly common 

 rust on Panicum capillare has been used in previous years for 

 sowings on 26 different species of hosts with no infection. 4 A 

 careful morphological study shows that the species in its uredinial 

 and telial conditions is very like Puccinia Pammelii Arth. (P. 

 Panici Diet.), occurring commonly on Panicum virgatum, whose 

 aecia have been grown upon Euphorbia corollata. Since this fact 

 was ascertained, attempts have been made to grow P. emaculata 

 upon Euphorbia corollata. Telial material from the vicinity of 

 Lafayette, Ind., was sown accordingly on April 28, 1913, March 

 24, 31, and April 6, 1914. Material collected by Dr. Fromme at 

 Lakehurst, N. J., was sown May 8, 19 14, on both E. corollata and 

 E. cyparissias. A collection from Lafayette was also sown March 

 31, 1914, on Chelone glabra, and Dirca palustris, which had not 

 previously been tried. All attempts were equally fruitless. It is 

 hoped that some time a fortunate field observation may lead to 

 the solution of the problem. 



4. Uromyces Rhyncosporae Ellis. No satisfactory field 

 clues to the alternate host of this species have yet been obtained. 

 Morphological study has led to the suggestion, improbable as it 

 may seem at first, that it can belong to the very common Carcx- 

 Aster-Solidago complex. To test this suggestion, material ob- 

 tained by Dr. Kern and the writer at Auburn, Ala., was sown 

 April 22, 1912, on Aster paniculatus, Solidago canadensis, and 

 Helianthus angustifolius. Another set of sowings was made on 

 A Fay 8 following upon other plants of the same three hosts, and 

 on RucUia strepens, and Apocynum cannabinum. No infection 



3 Jour. Myc. 14: 20. 1908. 



* Bot. Gaz. 35: 12. 1903; Jour. Myc. 8: 52. 1902; 10: 10. 1904; 12: 12. 

 1006; 13: 192. 1907; 14: 11. 1908; and Mycol. 1: 230. 1909. 



