174 IOWA ACADEMY OF SCIENCES. 



NOTES CONCERNING IOWA LICHENS. 



BRUCE FINK. 



It has been my good fortune, through connection with the 

 Minnesota Botanical Survey, to. be able to study the lichen- 

 flora of a region extending from northeastern Iowa to the 

 British possessions; and it is my purpose first of all to give a 

 somewhat revised abridgment of a previous paper* dealing 

 with the lichen-floras of certain localities within this region. 

 The localities are Fayette, Iowa; Pictured Rocks, Clayton 

 county, Iowa; and Minneapolis. I had originally intended to 

 present merely an abstract of the original paper, but have 

 finally decided that the only way to do justice to the subject is 

 to give a more extended account from an lowan point of view. 



Also, in the interval of three years since my paper on Iowa 

 lichensf appeared, I have been able to add a number of species 

 new to the state, and a list of them is given at the close of the 

 paper. The further study of areas within and without the limits of 

 Iowa has gi ven additional knowledge of the distribution of a few 

 species previously reported, and I shall give some notes con- 

 cerning these, stating why they are of special interest and in 

 some instances where they are likely to occur in our state. 



The only noteworthy differences between the vicinities of 

 Fayette and Minneapolis as regards substrata suited to lichen- 

 development are the presence of the Saint Peter sandstone at 

 the latter place, which does not occur at the former, and the 

 fact that the paleozoic limestones outcrop at the surface much 

 more frequently at the former. The first difference is in favor 

 of the lichen-flora about Minneapolis, and the second favors 



* Contributions to a Knowledge of the Lichens of Mlnnesot i, II Lichens of Minne- 

 apolis and VlclDity, Minn. Bot. Stud., Bull. No. 9, parts X and XI, pp. 703-726. 



+ Lichens of Iowa, Bull. Lab. of Nat. Hist., State Univ. of Iowa, vol. Ill, No. 3, pp. 



