TYPICAL SWAMP AREAS. 49 
is a typical dense shade shrub, is found abundantly. On 
Beaver Island there are added Salix rostrata, Populus bal- 
samifera and Ledum latifolium. Among the herbs, the 
shade loving ferns, Osmunda regalis, Botrychium Virgini- 
anum and Cystopteris bulbifera are prominent, while in 
the more open spots where there is abundance of water, 
Scutellaria lateriflora, Lycopus Virginicus, Impatiens pal- 
lida, and Epilobium coloratum are most characteristic. In 
the Beaver Island area the swamp is much drier and soil 
herbs are more typical. 
Among these Symplocarpus foetidus is very common. 
The most abundant low herbs in both areas are Linnaea 
borealis, Dalibarda repens, Viola blanda, Coptis trifolia, 
Chiogenes serpyllifolia, Clintonia borealis and Galium 
triflorum. Marchantiaand Conocephalus grow abundantly 
in the wetter places while the mosses luxuriate upon the 
logs. Hypnum crista-castrensis, Climacium dendroides, 
Thuidium delicatulum, Dicranum scoparium, Mnium syl- 
vaticum and Sphagnum squarrosum are among the domi- 
nant forms. Later stages in the history of the arbor-vitae 
swamp may be observed in the region about Little Traverse 
Bay on the main land. 
Along the outlet of Roaring Brook, the conditions are 
mesophytic at present, though the most characteristic 
plants are still the same as those in the typical area just 
described. Associated with them, however, are the rap- 
idly encroaching plants one might expect to find in such a 
mesophytic area, and here may be seen the probable 
destiny of the arbor-vitae swamp. Notable among these 
plants are Aralia nudicaulis, Trientalis Americana, Lyco- 
podium lucidulum, Cornus Canadensis, Maianthemum 
Canadense and Streptopus roseus. 
4, THE PRAIRIE SWAMPS ABOUT CHICAGO. 
Lake Calumet is one of a series of small lakes which 
occupy the lower depressions of old Lake Chicago. Other 
4 
