232 MINNESOTA BOTANICAL STUDIES. 



highest portion of the State, reaching 2,230 feet, and the region 

 gave five arctic or subarctic species of a total of eleven collected 

 only here. The influence of elevation becomes apparent when 

 we compare the Misquah hills area with the Gunflint region as 

 to number of northern species. The latter locality lies 20 miles 

 north of the former and about 400 feet lower, only a small por- 

 tion of it near the Paulson mines reaching 2,000 feet. The 

 Misquah hill area which is a more extended region of higher 

 elevation furnished the goodly proportion of northern forms 

 noted above while the Gunflint area gave only one such species 

 in a total of twelve found only in the area. 



Of all the species found only in one place 25, or more than 

 one-fourth, are arctic or subartic and 71, or approximately 

 three-fourths are plants characteristic of temperate regions. 

 Without entering into the yet more complicated analysis which 

 a consideration of these rare temperate region plants would 

 involve, a mere inspection of the table will show in a general 

 way that their distribution is just the reverse of that of the north- 

 ern species, or that they are especially characteristic of that 

 small portion of the region studied which lies to the north of the 

 divide and of the southern portion of the region lying between 

 the divide and lake Superior. Of course it could also be 

 shown that they are more especially characteristic of the lower 

 elevations. 



Of the 63 species collected only in two or three places, only 

 a half dozen are arctic or subarctic species, and it would have 

 been useless to give the whole 63 in tabular form as no safe 

 data could be obtained from so small a proportion of northern 

 species. However, the 6 northern species are as follows : 



Ramalina pusilla (Prev.) Tuck. var. geniculata Tuck. 



Parmelia encausta (Sm.) Nyl. 



Sticta scorbiculata (Scop.) Ach. 



Lecanora frustulosa (Dicks.) Mass. 



Lecanora sordida (Pers.) Tii. Fr. 



Buellia geographica (Pers.) Tuck. 



In order that we may have all of the northern species before 

 us for a final consideration, I shall give a list of those generally 

 distributed as follows : 



Lecidea lactea Fl. 



