430 BOTANICAL GAZETTE [DECEMBER 



WEST LAKE. 



This lake, situated three miles north of Chelsea (Sec. 30, Dexter 

 Tp.), is also known locally as Johnson's Lake. In area it is slightly 

 more than a fourth of a square mile (65 hectares). The margin of 

 the lake originally extended a half mile (o.8 km ) farther west and 

 southwest. This part is now occupied by a partially floating bog. 

 The north, south, and east shores are sandy and low. Patches of 

 bulrushes and water-lilies occur here and there over the lake and show 

 its generally shallow character. Toward the east there is a narrow 

 swampy outlet by which its water after a long and circuitous route 

 reaches the Huron River. There are no streams tributary to the 

 lake. The basin lies near the southeastern margin of the interlobate 

 moraine, and is bounded on the north and south by hills 60 to 80 feet 

 (i8-24 m ) in height. Not all of the original extension to the southwest 

 has been filled by peat; two small areas of open water still remain. 



The shores, with the exception of the western side, support a 

 vegetation similar to that of many lakes in this region. Three 

 societies of plants may be distinguished. 



Aquatics. The most abundant plants are Scirpus lacustris, 

 Castalia tuberosa, and Sagittaria rigida. These occur not only along 

 shore, but in shallow water throughout the lake. Associated with 

 these are Naias flexilis, Brasenia purpurea, Potamogeton heterophyl- 

 lus, Chara (sp.), Spirodela polyrhiza, Vallisneria spiralis, Scirpus 

 americanus, and Decodon verticillatus. 



Sedge-grass society. Very near the north, south, and east shores 

 occur a great number of species of grass-like plants. Their associations 

 vary greatly at different parts of the shore line. The dominant forms 

 are Carex filiformis, Panicularia nervata, Eleocharis palustris, Carex 

 teretiuscula, C. Muskingumensis, Dulichium arundinaceum, Panicu- 

 laria Canadensis, Dryopteris Thelypteris, and Scutellaria galericulata. 

 Among the species of secondary importance are Onoclea sensibilis, 

 Carex riparia, C. stipata, C. hystricina, C. interior, Spartina cynosur- 

 oides, Typha latifolia, Iris versicolor, Lobelia Kalmii, Comarum 

 palustre, Lycopus americanus, and Eupatorium maculatum. Closely 

 associated with these plants are the seedlings of the shrubs and trees 

 which make up the next society. 



Willow-maple society. The shrub and tree border is composed, 



