308 



Mycologia 



Aster, or we have a second species of Coleosporium attacking 

 species of Aster. The problem requires a further investigation 

 before a definite solution is obtained. 



Again, it must be noted that in the one experiment with aecio- 

 spores from aecia on Pinus contorta collected in Montana, 5 

 plants of Aster were inoculated, of which 3 were infected, and 

 6 plants of Solidago, all from the most susceptible species, were 

 inoculated without infection. This indicates that this collection 

 of aecia belonged to an Aster rust. The writer has collected the 

 aecia of this rust on Pinus contorta in two regions in the west, 

 one near Bozeman, Montana, the other in Estes Park, Colorado. 

 The aecia in both cases were beyond maturity and immediately 

 adjacent to the infected pine trees were infected plants of species 

 of Aster which bore the uredinia of the Coleosporium. No in- 

 fected plants of Solidago were found in either locality. In our 

 inoculation experiments just given, 6 trees of Pinus contorta 

 failed of infection when, inoculated with the sporidia from the 

 telia of the eastern form of the rust, although trees of Pinus 

 rigida and P. scopulorum were abundantly infected from the same 

 exposure under the same conditions. These results indicate that 

 the western Aster rust may be distinct from the western Solidago 

 rust which is probably identical with the eastern Solidago rust. 



The aecia of Coleosporium solidaginis like those of Coleo- 

 sporium carneum vary greatly in size, depending on the size of 

 the needles of the species of pine infected. Those of C. soli- 

 daginis on pines with small needles, such are Pinus echinata and 

 P. pungens (PL 23, fig. 1), are smaller than those on P. rigida, 

 P. scopulorum, and P. taeda (PL 23, fig. 2). The pycnia and 

 aecia of Coleosporium solidaginis are aggregated or clustered. 

 Those of C. carneum (PL 23, fig. 3) on a given host are larger 

 than those of C. solidaginis (PL 23, fig. 2), and are borne in more 

 or less extended rows. The pycnia of C. solidaginis in color are 

 grenadine-red to mahogany-red, those of C. carneum, orange- 

 rufous to auburn or chestnut. 



Coleosporium solidaginis has been reported as occurring nat- 

 urally in its aecial stage upon 14 species of pine, chiefly in the 



