INTRODUCTION. 



xxxvii 



Pepin, on the Upper Mississippi, of the water-shed which gives origin both to it and 

 the Maskeg Fork of Bad River, flowing into Lake Superior. 



It will be perceived that the preceding pages form a synopsis, only, of the conclu- 

 sions derived from very extensive observations of the leading features of the coun- 

 try explored, unencumbered with details. These details, however, furnishing as 

 they do the data whence these conclusions have been drawn, are of paramount 

 importance, and constitute, in fact, the body of the Report herewith submitted. 



Being desirous to collect as much general scientific information as possible, with- 

 out interfering with the main objects of the Survey, I instructed the members of 

 the corps, when not otherwise engaged, to record observations, and preserve speci- 

 mens in those departments of natural history in which they were most proficient. 

 Accordingly, Dr. Parry, who has a good knowledge of Botany, has reported to me his 

 observations made in this branch of science, on the St. Peter's River, and the country 

 lying between the Mississippi River and Lake Superior. Here I shall merely touch 

 upon a few of the general results, referring the Department for further information 

 to Dr. Parry's own report. 



Where there is a lithological as well as a palseontological passage from one 

 geological formation to another, there is a simultaneous change in the botany of the 

 country. This is especially observable in the influence of the trap ranges. The 

 vegetation superincumbent on that formation is so marked, that it may often serve 

 to detect it when the rocks themselves are hidden from view. 



The drifVdeposits of the St. Peter's support a peculiar growth, among which the 

 following are the most striking : Castilliga sessili flora, Psoralea esculenta (Pomme de 

 prairie, or Bread root), Oenothera surrulata, Oxytropis Lambertii, Lygodesmia juncea, 

 Ortliopogon oligostracliyum. These contrast strongly with the plants which charac- 

 terize the drift-deposits occupying the height of land between the Mississippi and 

 Lake Superior, which are Pinus Banksiana, Vaccinium tenellum (whortleberry), Gaul- 

 theria procumbens ( wintergreen) , and some species of Lycopodiums, proving a 

 decided difference in the two regions, both in the composition of the beds of drift 

 and the soil derived therefrom. 



On the shores of Lake Superior, Dr. Parry found a singular blending of littoral 

 and Alpine plants, as for instance Lathy rus maritimus (beach pea), and Hudsonia 

 encoides, common to the Atlantic sea-beach, associated with PotentiUa tridentata, 

 Cenomyce rangiferina, common to Alpine and Arctic regions. These are adduced 

 to show the combined influence of soil and atmosphere on vegetation. 



Dr. Parry was instructed to collect as much information as possible with regard 

 to the economical and medicinal applications of plants, used by the Indians. 

 Several of their most important native articles of food, as he justly remarks, are 

 found in regions where we might least expect to find the means of subsistence ; 

 thus, the wild rice fringes the innumerable lakes and rivers of this northern Indian 



