XLIII. CONTRIBUTIONS TO A KNOWLEDGE OF 



THE LICHENS OF MINNESOTA— II. LICHENS 



OF MINNEAPOLIS AND VICINITY. 



Bruce Fink. 



CONSIDERATIONS OF DISTRIBUTION AND HABITAT. 



This paper is based upon collections made by me during the 

 summer of 1896 in the outskirts of Minneapolis, or within six 

 miles of the city limits. As stated in the preceding paper, 

 the lichen-flora of that portion of Minnesota from Minneapolis 

 south is essentially similar to that of northern Iowa. After 

 having worked over portions of this latter area thoroughly, I 

 was quite as much interested while collecting at Minneapolis 

 to ascertain how the two regions bordering on the Mississippi 

 river compared with reference to their lichen floras as in ques- 

 tions purely local. Indeed, in no way can plant-distribution be 

 studied better than by comparing different areas, and I shall 

 attempt to draw some conclusions, from my study of certain 

 localities, concerning lichen-distribution in the region now un- 

 der consideration. 



The first thing that impressed me in the study of the region 

 about Minneapolis is that lichens are not so numerous there 

 either as regards species or individuals as in some other parts 

 of Minnesota, or in certain equal areas in northern Iowa. I 

 have made a collection of about 220 species at Payette. Iowa, 

 of which 180 species were listed in my paper upon the lichens 

 of Iowa. These numbers are given for the whole county of 

 Fayette, but, for purposes of comparison, all species not with- 

 in five miles of the city of Fayette are cut out, as will appear 

 in a table to follow. 



The only noteworthy differences between the vicinities of 

 Minneapolis and Fayette as regards substrata suited to lichen- 

 development are the presence of the Saint Peter sandstone at 



