Cultures of Uredineae in 1916 and 1917 309 



forms of rust on Car ex going 'to Ribes, P. Grossulariae (Schum.) 

 Lagerh. (P. uniporula Orton), 16 we seem justified in assuming 

 that the grass forms in question represent one species made up of 

 morphologico-physiological races, just as the sedge forms appear 

 to do, but the proof is not so complete. The marked differences 

 in the urediniospores of P. Sporoboli, P. Cryptandri and U. Sporo- 

 boli, are all such as can be harmonized with the assumption that 

 the three forms represent only the races of one species, although 

 it does not seem necessary now to go into the required explanation 

 to make the matter perfectly clear. However, for convenient 

 taxonomic reference, and until the relationship is more firmly 

 established, it will be best to treat P. Sporoboli, P. Cryptandri 

 and U. Sporoboli as independent species. 



2. Uromyces on Spartina. — Field observations by Dr. J. F. 

 Brenckle were made during the spring of 191 5 at Kulm, N. Dak., 

 which seemed to indicate connection between aecia on V agnera 

 stellata and the common Uromyces on Spartina. Such a con- 

 nection seemed to be strengthened by later observations. On May 

 31, 1916, Dr. Brenckle says in a letter to the author: " Yesterday 

 I went over my station carefully and found the infected plants 

 of Smilacina [Vagnera] invariably accompanied by rusted Spar- 

 tina. I noted also a number of well infected leaves, each of 

 which was overhung and scraped on by a rusted leaf of Spartina. 

 As the infection of Smilacina is only in the pycnial state it prob- 

 ably has not spread away from its original telial source. The 

 Smilacina is abundant but the infected plants are sharply con- 

 fined to those patches also inhabited by the Spartina. One such 

 patch had plants of Smilacina which were not infected. I was dis- 

 appointed that my theory was not proving correct until I noticed 

 that the Spartina had no rust." 



With such strong circumstantial evidence the success of cultures 

 undertaken with telial material supplied by Dr. Brenckle still came 

 as a surprise, for three or four races of the Uromyces on Spartina 

 are already well known having aecia on three families of dicoty- 

 ledonous hosts, and no heteroecious rust has heretofore been dis- 

 covered having aecia on both monocots and dicots. 



On May 11 teliospores from Spartina Michauxiana were sown 



16 Mycol. 4: 13. 1912; 7: 66, 78. 1915. 



