Fink: LICHENS OF NORTHWESTERN MINNESOTA. 679 



Calicium trabinellum (SCHAER.) KBR. 



Calicium parietinum ACH. 



The similar formations were studied at Bemidji and Red 

 lake, and the species marked (C) were found in each of the 

 three formations. For Bemidji may be added Biatora virides- 

 cens (Schrad.) Fr, and for both Bemidji and Red Lake, Cetraria 

 juniperina (L.) Ach. var. pinastri Ach. Although occurring 

 in the same area as the second formation above on the living 

 tamaracks, the present one will be found by comparison to be 

 quite distinct both as to genera and species. 



Growing in moist areas, the lichens of the formation are 

 almost uniformly those which rise more or less from the sub- 

 stratum. Nearly all are the Cladonias and Caliciums, which 

 have podetia rising erect from the substratum and are protected 

 on all sides by a pseudo-cortex of densely interwoven hyphae 

 running in a longitudinal direction. 



The earth lichen formations of the swamps were carefully 

 noted and were found to be essentially like those of Cladonia 

 formations of rotten wood recorded above, at least as to genera. 

 I shall record the formation provisionally that it may be further 

 studied and shall name it for a variety of Peltigera thus far 

 found in the state only in the swamps. 



PELTIGERA CANINA LEUCORRHIZA LICHEN FORMATION OF 

 EARTH IN TAMARACK SWAMPS (BEMIDJl). 



Peltigera canina (L.) HOFFM., C. 



Peltigera canina (L.) HOFFM. var. leucorrhiza FLK., C. 



Cladonia cariosa (AcH.) SPRENG., R L. 



Cladonia pyxidata (L.) FR., C. 



Cladonia gracilis (L.) NYL. var. verticillata FR., C. 



Cladonia gracilis (L.) NYL. var. hybrida SCHAER., C. 



Cladonia cenotea (Acn.) SCHAER., R L. 



Cladonia furcata (Huos.) FR., B and H. 



Cladonia rangiferina (L.) HOFFM., C. 



The similar formations were studied at Henning and Red 

 lake. Those marked (C) are common to the three formations, 

 those marked (R L) were found at Red lake only and the one 

 marked (B and H) at Henning as well as at Bemidji. The 

 adaptations of the plants of these formations are, of course, the 

 same as those of the lichens of the Cladonia formations of 

 rotten wood. 



