280 MINNESOTA BOTANICAL STUDIES. 



northeastern Iowa, a portion of a State not so thoroughly sur- 

 veyed and only having 226 known lichens, has 26 lichens not 

 yet found in Minnesota, shows that the study of Minnesota 

 lichens is by no means yet approximately completed, since a 

 large part of these 26 rare or obscure lichens found already 

 within 50 miles of the state certainly exist within its bord- 

 ers in the southeastern portion, and other unstudied portions 

 of the state may yet be expected to bring additions to the 

 lichen flora in like proportion. A list of these 26 lichens could 

 be added with habitats to aid in their discovery in southeastern 

 Minnesota but an inspection of another paper* will give the 

 names of them. 



A study of the table above, giving habitats and number of 

 species for each, by per cents, would give a somewhat larger 

 per cent, of lithoph3'tic lichen species for the two areas consid- 

 ered than a former study exhibited for the Minneapolis and 

 Iowa localities and about the same per cent, as the lake Superior 

 region. I subjoin, arranged according to habitat, a list of the 

 41 lichens added to the state in this paper. From the list it wilL 

 be seen that more than half of these species are most common 

 on rocks, and that the great Archean and Algonkian masses 

 exposed throughout the upper valley alone produced one-third 

 of them. For convenience of reference to the above statements 

 I shall now add the table, placing rock species first, and then 

 follow the list with further discussion. 



New to Minnesota on Archean or Algonkian rocks. 

 Ramalina polymorpha (Ach.) Tuck. 



Parmelia saxatilis (L.) Fr. var. panniformis (Ach.) Schaer. 

 Pyrenopsis phaeococca Tuck. 

 Pyrenopsis melambola Tuck. 

 Omphalaria phyllisca (Wahl.) Tuck. 

 Leptogium pulchellum (Ach.) Nyl. 

 Lecanora sp. 



Lecanora subfusca (L.) Ach. var. allophana Acii. 

 Lecanora cinerea (Pers.) Nyl. var. cinereoalba var. nov. 

 Rinodina sophodes (Ach.) Nyl. var. tephraspis Tuck. 



* Fink, B. Review of Lichen0l0gic.1l Studies in the Upper Mississippi Valley, 

 with suggestions for future investigations. In list to be published in Memoirs 

 of the Torrey Botanical Club. 



