254 



Mycologia 



of the species of Coleosporium in the eastern United States from 

 pycnial characters, where freshly collected specimens are available. 



Coleosporium delicatulum 



Coleosporium delicatulum (Arthur & Kern) Hedge. & Long 

 was first described in the aecial stage by Arthur and Kern 16 in 

 1906 as Peridermium delicatulum. Proof of the connection of the 

 aecial stage on Pinus rigida with the uredinial stage on Euthamia 

 graminifolia was obtained by Dr. Long and the senior writer 17 and 

 published in 191 3. 



Inoculations with Coleosporium delicatulum have since been 

 made as follows: During April and May, 1913, nine sets of inocu- 

 lations were made with aeciospores from collections of aecia made 

 on Pinus rigida near Takoma Park, D. C. The following plants 

 were inoculated: 1 Aster conspicuus, 2 A. cordifolius, 3 A. eri- 

 coides, 1 A. hesperius, 1 A. laevis geyeri, 3 A. lenta, 1 A. panicu- 

 latus, 3 A. undulatus, 14 Euthamia graminifolia, 2 Helianthus 

 divaricatus, 1 Ribes nigrum, 4 Senecio aureus, 4 Solidago bicolor, 

 2 S. canadensis, 2 S. erecta, 5 S. juncca, 2 S. multiradiata Ait., 3 

 S. rugosa and 1 speciosa. Of these plants only those of Eu- 

 thamia graminifolia were infected, having mature uredinia in 14 

 to 16 days and telia in about 2 months. 



During May and June, 1914, three sets of inoculations were 

 made with aeciospores from the same source as in 191 3. Plants 

 of the following species were inoculated: 1 A. laevis, 3 A. laevis 

 geyeri, 1 A. undulatus, 1 Elephantopus tomentosus, 18 Euthamia 

 graminifolia, 1 Helianthus occidentalis, 2 Solidago canadensis, 2 

 S. multiradiata, 3 5\ rugosa and 2 Vernonia noveboracensis. Of 

 these plants only those of Euthamia were infected and bore ure- 

 dinia and telia as in the preceding experiments. 



Aeciospores from aecia collected on Pinus palustris by Dr. Long 

 at Brooksville, Fla., March 27, were used April 3, 1914, to inocu- 

 late plants of the following species : 3 Euthamia graminifolia, 1 

 Eupatorium maculatum and 1 Solidago rugosa. The plants of 

 Euthamia were infected and bore uredinia and telia as before. 



is Arthur, J. C, & Kern, F. D. North American Species of Peridermium. 

 Bui. Torrey Bot. Club 33: 404. 1906. 



17 Hedgcock, Geo. G., & Long, W. H. Notes on Cultures of Three Species 

 of Peridermium. Phytopathology 3: 250. 19 13. 



