194 



incorrect because of the label, "along railroad." So far as I am able to learn, 

 the plant has not spread with the rapidity to be expected from tiie variety Tragus. 

 In view of the accuracy of Mr. Hill in all of his determinations, the Lake County 

 station is admitted, with the suggestion that the plant in that particular locality 

 needs a much closer study. 



The Noble County plant is unmistakable, not only in its characters, but in its 

 habits of growth. From facts ascertained through the work of Supt. Van Gorder, 

 it is safe to say that if the Russian thistle spreads throughout Indiana it will be 

 from the Noble County station as a center. The plant has been carefully watched 

 since its first appearance in 1893, and efforts made to prevent its spread, though 

 with no very great success, as the following letter indicates : 



Brimfield, Inc., Nov. 3, 1895. 

 Mr. W. B. Van (iorder, Knight.^toirii, Lid.: 



Dear Sir — In reply to yours of some time ago, will say that the Russian 

 thistle came up again this year worse than last year. It was not cut soon enough, 

 which, of course, scattered the seeds. I have not heard of it any place else 



yet. * ■•■■ * ■••' J. E. NiSWANDER. 



In the last map issued by the United States Department of Agriculture, 

 showing the distribution of the Russian Thistle, a location is given in south-cen- 

 tral Indiana. The map is, however, so small that I have not been able to locate 

 the station, nor have I been able to discover upon what authority it was added. 



In my opinion there are not more than two stations for the Russian Thistle 

 in the State. Of these, that in Noble County alone seems to threaten any great 

 spread of the pest. AVhile the plant should be carefully watched, its general 

 character as to periods of flowering and maturation of seed, taken in connection 

 with the fact that though known to exist in Indiana since 1892, it has yet made 

 no marked advance, would indicate that the danger from its introduction has 

 been overestimated. 



Polygonum tenue Michx. "Sand hills. Pine Station, Ind., July 28, 1875." 

 (E. J. Hill.) Tippecanoe County, 1893. (Stanley Coulter.) This species has 

 perhaps a more general distribution throughout the State than the references 

 would indicate. Its normal range easily includes our territory, yet so far as I 

 know no other stations are recorded. In a study of the genus Poh/gonion made re- 

 cently I examined all of the collections in the State, and it is certainly not found 

 in them from any other localities. Tlie species is sufficiently characteristic to be 

 easily separated from the more common forms, and could scarcely be confused 

 with any other species, if we except P. rumoxv^simum Michx., from which it is 

 readilv distinguished bv the character of the achenes. 



