4 METASPERMAE OF THE MINNESOTA VALLEY. 



central river of North America, emptying its waters into the 

 Gulf of Mexico. There may be distinguished then, these three 

 drainage-basins, and each might be a suitable district for study 

 along the lines contemplated in the establishment of a botanical 

 survey. It happens however that the Mississippi drainage -area 

 in Minnesota admits of a natural subdivision. The Minnesota 

 river which joins the larger, but geologically newer stream, at 

 Ft. Snelling, is in many ways the most interesting portion of 

 the Mississippi basin. As will be shown later, in the special 

 chapter devoted to this valley, the Minnesota is peculiarly 

 central in its location and remarkably interesting, not only 

 from its topography and situation, but on account of its history 

 as well. 



Occupying the position that it does the Minnesota valley, 

 while a subsidiary drainage-basin, becomes one of first import- 

 ance in Minnesota. It is, therefore, the natural region which 

 has been chosen for study at this time. Later, it is hoped, the 

 other basins to which the superficial area of Minnesota may be 

 referred, will receive attention. Thus a final report of the 

 botanical survey will knit together the data acquired through 

 the consecutive investigation of the different natural districts 

 making up the state. For the purpose of the botanical division 

 of the Geological and Natural History Survey, then, the state 

 of Minnesota may be considered as presenting these divisions: 



(3. 



I. Rainy Lake river drainage-basin 11,347 sq. m. 



II. Red river drainage-basin 18,106 sq. m. 



III. Lake Superior drainage-basin 7,689 sq . m. 



IV. Minnesota river drainage-basin 15,706 sq. m. 



V. Rock river drainage-basin 1,929 sq. ni. 



VI. Des Moines river drainage-basin 1,639 sq. m. 



VII. Cedar River drainage-basin 1,206 sq. m. 



VIII. St. Croix river drainage-basin 3,669 sq. m. 



IX. Other tributaries of Miss, below St, Paul 6,399 sq. m. 



X. Central Mississippi drainage-basin 16,596 sq. m. 



Total area of Minnesota 84,286 sq. m. 



Only the 4th and 10th of these basins are peculiarly Minne- 

 sotan (disregarding the unclassified IX. div.). Of these two 

 the Minnesota is much the older and more interesting area, as 

 will be discussed later. 



History of botanical investigation in the Minnesota valley. 

 In the earlier published works relating to the plants of Minne- 

 sota it is not possible to determine accurately what references 



(3Vi). Hall: Physiographic Conditions of Minnesota. Proc. Hort. Soc. 393 (1884). 



