134 
Mycologia 
6. PucciNiA Seymouriana Arth. (Aeciditim obesum Arth.). — 
This rust on Spartina at the time it was described in 1902 was 
predicted upon morphological and geographical grounds to have 
its alternate form upon the Rubiaceous genus Cephalanthus,'^* the 
prediction being established by cultures in 1905, and confirmed 
in subsequent seasons.^® It was not until June, 1913, that addi- 
tional suggestions came to light, when Rev. J. M. Bates wrote that 
his observations in the field led him to believe that in Nebraska 
this rust on Spartina was connected with an Aecidium on Apo- 
cynum hypericifolium. He sent a specimen of the aecia, which 
proved to be Aecidium obesum Arth. This collection was distrib- 
uted as 41OS of Barth. Fungi Columbiani, and lyoi of Barth. N. 
Amer. Ured. Later in the year a careful microscopic comparison 
of these aecia with those on Cephalanthus established their essen- 
tial similarity. Owing to adverse seasonal conditions Mr. Bates 
was unable to supply culture material for the 1914 cultures, but 
on May 8, 1915, he sent telial material on Spartina Michauxiana 
from Eight Mile Creek, near Red Cloud, Neb. It was sown May 
12, on Apocynum cannabinum, Amsonia salicifolia, Asclepias syri- 
aca, and Cephalanthus occidentalis, producing a scanty infection 
only on Apocynum, pycnia showing June 10, but without develop- 
ing aecia. 
A specimen of aecia on Asclepias pulchra, collected by INIr. Roy 
Latham, of Orient, N. Y., June 29, 1914, w^as reported to the 
collector upon cursory examination only, as aecia of Puccinia 
Jamesiana, that being the only species at that time known to have 
aecia with a limited mycelium on Asclepias, and it was suggested 
that he search for telial material on Bouteloua. Not long after- 
ward he wrote that Bouteloua was not known upon Long Island, 
and that among the infected milkweeds, which occur on “a patch 
about 100 feet in length by 25 in width, many plants being actually 
covered from ground up, stem, leaves, and all,” the only grass or 
sedge bearing r\.\sivias,Spartinacynosuroides,oi which he sent leaves 
covered thickly with telia remaining over from the preceding year, 
and young leaves of the season with uredinia. The Spartina rust 
Bot. Gaz. 34: 13. 1902. 
15 Jour. Myc. 12:24. 1906; Mycol. 1:236. 1909; 4: 19. 1910. 
