186 MINNESOTA BOTANICAL STUDIES. 



Peltigera canina (L.) HOFFM. var. spongiosa TUCK. 



Peltigera aphthosa (L.) HOFFM. 



Peltigera horizontalis (L.) HOFFM. 



Cladonia pyxidata (L.) FR. var. neglecta (FLK.) MASS. 



Cladonia gracilis (L.) NYL. (a variety not carefully noted). 



Cladonia furcata (HUDS.) FR. ? 



The Cladonias previously included in such formations seemed 

 here also to form an essential though plainly subordinate portion 

 of it and have been retained. The Peltigeras are the largest 

 forms known to the writer, and, in their wet and more or less 

 shaded habitat, reach unusual size. Three or four of them may 

 be found in almost any such swamp of the region, and detailed 

 statement as to which occur in a given swamp would be of little 

 or no value. The adaptations were briefly summed up in the 

 last paper of this series, and nothing need be added, except to 

 state that lying prostrate on the moist earth or mosses of the 

 swamp and partly out of reach of winds, the plants have an 

 abundance of moisture, seldom being dry as their related forms 

 on higher ground, and hence the usual luxuriance. 



The last of the previously recorded formations to be noted is 

 the Biatora lichen formation of mosses. This was found well 

 developed at Beaudette, Koochiching and Rainy Lake City. 

 The last locality furnished all of the species recorded for Bem- 

 idji in the last paper of this series, and Biatora sanguineoatra 

 Fr. may be added, and each of the other two localities showed 

 three of them. The adaptations have been discussed previously, 

 nor is it necessary to reproduce the list of five species. 



Proceeding to formations not previously recorded, first may 



be considered the following : 



*, 



POPULUS LICHEN FORMATION (WARROAD). 



Ramalina calicaris (L.) FR. var. fastigiata FR. 



Cetraria ciliaris (AcH.) TUCK. 



Evernia prunastri (L.) ACH. 



Usnea barbata (L.) FR. var. florida FR. 



Theloschistes polycarpus (EHRH.) TUCK. 



Parmelia tiliacea (HOFFM.) NECK. 



Parmelia saxatilis (L.) FR. 



Parmelia olivacea (L.) ACH. 



Parmelia conspurcata (SCHAER.) WAINIO. 



Physcia stellaris (L.) TUCK. 



