229 



approximately 250 rniles distant. That the fungus at least sometimes win- 

 ters over is evidenced by the fact that it has been collected in the vicinity 

 of Lafayette on rosettes of the host as early in the season as May 6. There 

 is little or no doubt that it had wintered in the unredinial stage, probably 

 as mycelium in the living leaves of the host. 



Perhaps the clearest indication of the survival of the winter by uredi- 

 niospores or mycelium outside of the Aecidiaceae occurs in Coleosporium 

 Solidaginis, on Solidago, Aster, and a few other Carduaceous hosts. This 

 species is very widespread throughout the United States and is exceedingly 

 common. Its exceeding commonness is attested by the fact that its Indiana 

 distribution is represented in the Arthur herbarium by 44 mounted collec- 

 tions and a few unmounted ones, from 10 counties, and extending over a 

 period of time from 1890 to the present. The aecial stage, Peridermium 

 (I'icolum, occurs on Pinus pungens and P. rigida, with a distribution from 

 Massachusetts and central New York to central North Carolina. According 

 to Sudworth's maps 33 Pinus rigida is the one of these two aecial hosts which 

 is nearer this section. Its nearest approach, as already shown, is eastern 

 Ohio, which is approximately 250 miles distant from Lafayette. This is a 

 greater distance than we would expect the fungus to migrate in one grow- 

 ing season ; but the fungus extends also much farther to the west and 

 northwest, so far, in fact, that it seems almost absurd to think it could 

 have spread so far from its aecial base in a season. Furthermore, the 

 writer on the first and second of July in 1912 made collections in eastern 

 Indiana which show that the species was already well established for the 

 season in a region a mile or more in extent. For such an infection, spores 

 must be present in some quantity or must be present very early. But this 

 is not the most convincing evidence at hand. There is a collection from 

 Lafayette on Solidago ulmifolia, made June 25, 1896, and one on 8. serotina 

 made May 15, 1901. There is also one on Aster corddfolius made May 30, 

 1S96, and one on Aster sp. indet. made May 12, 1902. This last collection is 

 on the rosette leaves of the plant which were practically in contact with 

 the ground, and the rust is well developed. The collection was actually 

 made earlier in the season than any aecial collection of the rust at hand 

 except one, which was made at Durham, N. C, May 3, 1910. The range for 

 the aecial collections is May 3 to July 6 ; and it was clearly impossible for 

 this specimen to have resulted from infection tracing back to ;eciospores 

 of the same spring. The circumstance seems to be much more easily ex- 



"1. c. Maps 26, 30. 



