88 The Rum River Valley as a Botanical District. 



28. 1888; N. H. Winchell. Geol. Nat. Hist. Sur. Minnesota, Final Rep., 



vol. 2. 



29. 1892. F. W. Sardeson. Bull. Minnesota Acad. Nat. vSci., vol. 3, p. 318. 



30. 1892. C. W. Hall and F. W. Sardeson. Bull. Geol. Society of A., vol. 



3, p. 350. 



31. 1892. W J McGee. U. S. Geol. Survey, 11th Ann. Rep., pp. 234 and 



330. 



32. 1893. C. R. Keyes. Iowa Geol. Survey, Ann. Rep., vol. 1, p. 24. 



33. 189.5. W. H. Norton. Iowa Geol. Survey, Ann. Rep., vol. 3, p. 180. 



34. 1895. Joseph F.James. Journal of Cincinnati Soc. of Nat. Hist., vol. 



17, p. 115. 



35. 1895. Samuel Calvin. Iowa Geol. Survey, Ann. Rep., vol. 4, p. 68. 



November 13, 1892. 



[Paper JS^.] 



THE RUM RIVER VALLEY AS A BOTANICAL 

 DISTRICT. 



E. P. Sheldon. 



The Rum river, with its tributaries, drains the surface 

 area of Mille Lacs, Isanti and Anoka counties. Besides this, 

 portions of Crow Wing and Aitkin contributory to Mille 

 Lacs lake, and the eastern edge of Morrison, Benton and 

 Sherburne counties are in its drainage basin. The valley is 

 thus seen to occupy a narrow strip lying between the Missis- 

 sippi drainage on the west and the St. Croix on the east. 



Within this narrow belt the most varied conditions for 

 plant growth are offered. It is to be noted that this section 

 is between that contributory area on the north and east 

 from which we would most naturally expect the entrance of 

 plants usually found occurring wherever large coniferous 

 belts are extant ; and the prairie-plant-contributing area on 

 the south and west, from whence we would expect the great 

 host of prairie composites, pulses, grasses, etc. 



Viewed in this light a stud^^ of the plant immigrants now 

 seeking a foothold in the valley becomes as interesting as a 

 review of the endemic plants. But we must remember that 

 in a very recent time in the history of our continent the 

 plants now considered endemic were emigrants from the 



