678 MINNESOTA BOTANICAL STUDIES. 
discussion of the Uszez formation of the pines, the plants may 
be adapted to the coniferous wood as well as to the moist habitat, 
it remains to be stated that the same species are both more 
numerous and more luxuriant in the swamps than on the upland 
pines. 
The following formation must be regarded as somewhat 
doubtful till further studied. 
STICTA PULMONARIA LICHEN FORMATION OF CEDAR SWAMPS 
(BEMIDJI). 
Sticta pulmonaria (L.) Acu. 
Nephroma levigatum Acu. 
Lecanora pallida (SCHREB.) SCHAER. 
Lecanora pallescens (L.) ScHAER. 
Pertusaria communis DC. 
Calicium chrysocephalum Acu. 
There is no doubt of the distinctness of the formation in 
the region as none of the plants were found elsewhere during 
the summer than in the cedar swamps, except the last which 
was also found in the tamarack swamps. The plants of the 
formation grow in dryer places in other regions and seem to be 
as well adapted to upland woods as many other lichens recorded 
for the tree formations of higher ground. 
The swamps afford yet one other characteristic formation 
well developed in the area studied wherever tamaracks and 
cedars flourish. It may appropriately be designated as follows: 
THE CALICIUM LICHEN FORMATION OF OLD LOGS AND STUMPS IN 
TAMARACK SWAMPS (HENNING). 
Ramalina pusilla (Prev.) Tuck., C. 
Cetraria ciliaris (Acu.) Tuck., C. 
Parmelia saxatilis (L.) Fr., C. 
Cladonia mitrula Tuck., C. 
Cladonia fimbriata (L.) Fr. var. tubeformis FrR., C. 
Cladonia gracilis (L.) Nyu., C. 
Cladonia gracilis (L.) Nyx. var. hybrida ScHarr., C. 
Calicium trichiale Acu. var. cinereum Nyt., C. 
Calicium trachelinum Acu. 
Calicium sp. 
Calicium curtum Turn. and Borr. 
