Hedgcock and Hunt: Notes on Coleosporium 249 



The aecial forms of the two species do not differ widely in mor- 

 phology, as is shown by the following table : 



Table of Comparison 



Coleosporium helianthi 

 Pycnia solitary or few, clustered, 

 deep chrome 10 to raw umber. When 

 fresh, 0.38 mm. wide by 0.5 mm. 

 long.11 



Aecia solitary or few, aggregated, 

 linguaform to flattened rhomboidal. 

 0.9 mm. high by 1 mm. long (plate 20, 

 fig- 2). 



Peridial cells 17 by 36 fx, walls 5 \x 

 thick. 



Aeciospores 16 by 27 fx, walls 2.6 fx 

 thick. 



Coleosporium inconspicuum 



Pycnia few to many, in extended 

 rows, yellow ochre to Dresden brown 

 when fresh, 0.28 mm. wide by 0.64 

 mm. long. 



Aecia few to many, aggregated or 

 in short rows, tubular to linguaform, 

 0.9 mm. high by 0.6 mm. long (plate 

 20, fig. 1). 



Peridial cells 20 by 38 /x, walls 

 4 fx thick. 



Aeciospores 15 by 25 fx, walls 2.4 fx 

 thick. 



The pycnia of Coleosporium inconspicuum are slightly darker 

 in color, and the aecia are more nearly tubular (Plate 20, fig. 1) 

 than those of Coleosporium helianthi, which are more commonly 

 flattened (Plate 20, fig. 2). 



The Coleosporium on Verbesina 



The Coleosporium occurring on Verbesina has been assigned by 

 Prof. Arthur to Coleosporium helianthi. In the experiments al- 

 ready mentioned with aeciospores of both C. helianthi and C. 

 inconspicuum all plants of Verbesina failed of infection. The 

 following inoculations were made with the Coleosporium from 

 Verbesina obtained in Florida : 



March 12, 1914, urediniospores from a collection made by Dr. 

 Long at New Smyrna, March 9, were used to inoculate the follow- 

 ing plants without infection : 1 Elephantopus carolinianus, 2 E. 

 tomentosus, 1 Solidago bicolor, 2 S\ juncea and 1 Vernonia glauca. 



March 11, 191 5, urediniospores from a collection by the senior 

 writer in the same locality, March 4, were used to inoculate suc- 

 cessfully 3 plants of Verbesina virginica, which bore uredinia 



10 Colors used are those of Ridgway, R. Color standards and nomenclature. 

 Washington, D. C. 1912. 



11 Measurements are based on an average of 60, 10 each for six different 

 collections. 



