306 MINNESOTA BOTANICAL STUDIES. 



Buellia parasema (Acn.) TH. FR., G. 



Buellia turgescens (NYL.) TUCK. 



Calicium parietinum ACH. 



Thelocarpon prasinellum NYL. 



The additions for Granite Falls are Cctraria ciliaris (Ach.) 

 Tuck., Lecidea entcroleuca Fr. and Calicium quercinum Ach. 

 As in other instances the common forms are those most charac- 

 teristic of such formations. I have not detected the Calicium 

 for which I have named the Mankato formations at Granite 

 Falls, where it is replaced by another species, and I shall add 

 the species, Acolium tigillare (Ach.) Dn., which is one of the 

 Calicei common in the similar formation at Fayette, Iowa, and 

 the only one found in the like formation at Minneapolis. It 

 must be admitted that the name used for these formations, while 

 it may be applied, is not so appropriate for the related forma- 

 tions in the lake Superior region where some of the Calicei 

 grow on living bark and yet others on rotting wood. 



But one formation remains to be considered, viz., that of rot- 

 ting stumps and prostrate logs. In these formations the most 

 common plants are those of the genus Cladonia and the forma- 

 tions may accordingly receive the following name : 



Cladonia formation of rotten 2uood (Mankato). 

 Peltigera canina (L.) HOFFM., G. 

 Peltigera canina (L.) HOFFM., var. sorediata SCHAER. 

 Cladonia fimbriata (L.) FR., G. 

 Cladonia fimbriata (L.) FR. var. tubaBformis FR., G. 

 Cladonia gracilis (L.) NYL., G. 

 Cladonia gracilis (L.) NYL., var. verticiilata FR., G. 

 Cladonia symphycarpia TUCK. 

 Cladonia macilenta (EHRH.) HOFFM. 

 Cladonia cristatella TUCK. 



The only species found at Granite Falls in the similar forma- 

 tion and not at Mankato is Biatora flexuosa Fr. and the forma- 

 tion may, with this addition, be indicated by marking (G) those 

 plants of the Mankato formation common to both. Comparison 

 with formations from other localities would show some varia- 

 tion, but the Cladonias would predominate and give character 

 to the formations. Wood commonly rots in moist shady places. 



