106 BOTANICAL GAZETTE [AUGUST 
tophyllum demersum, Naias flexilis, Potamogeton lucens, P. natans, 
P. zosieraefolius. 
II. Zone of water lilies —This zone is confined to shallow water 
seldom over 5 feet (1.5 m.) in depth. The characteristic plants 
are Castalia odorata, Nymphaea advena, Brasenia Schreberi. 
Ill. Zone of floating sedges—The mat formed by these sedges is 
very firm and usually about 18 inches (45.8 cm.) in thickness. The 
chief mat-forming plants are Carex filiformis and C. oligosperma. 
Associated with these, some playing an important part in mat- 
formation, are Menyanthes trifoliata, Dulichium arundinaceum, 
Eriophorum viridi-carinatum, Drosera rotundifolia, Aspidium Thelyp- 
leris, Onoclea sensibilis, Equisetum limosum, Eupatorium pur- 
pureum, E. perfoliatum, Mentha arvensis var. glabraia, Scutellaria 
galericulata, Utricularia sp., Calopogon pulchellus, Campanula 
aparinoides, Arethusa bulbosa, Galium trifidum, Aster junceus, 
Potentilla palustris, Solidago serotina var. gigantea, Lysimachia 
terrestris, etc. 
IV. Zone of bog shrubs—The characteristic plants of this zone 
are Chamaedaphne calyculata, Andromeda polifolia, Betula pumila, 
Nemopanthes mucronata, Sarracenia purpurea, Vaccinium Oxycoccus, 
V. macrocarpon. 
V. Zone of tamaracks.—The principal plants are Larix laricina, 
Cornus stolonifera, Osmunda regalis, O. cinnamomea, Rhus Vernix, 
Aster junceus. In areas where the tamarack is thick there is no 
undergrowth. 
VI. Zone of poplars and maples——This zone is often of great 
width for reasons pointed out in a previous paper (4), and has 
the greatest variety of species of any zone. Some of the plants 
found are Acer rubrum, A. saccharinum, Populus tremuloides, P. 
grandidentata, Prunus serotina, Quercus rubra, Q. bicolor, Sam- 
bucus canadensis, S. racemosa, Salix discolor, S. rostrata, Spiraea 
salicifolia, Cornus stolonifera, Ilex verticillata, Cephalanthus occi- 
dentalis, Rosa carolina, Epilobium adenocaulon, Verbena hastata, 
Solanum Dulcamara, Polygonum sagittatum, P. hydropiperoides, 
Geum rivale, Rumex britannica, Impatiens biflora, Viola blonda, 
Solidago canadensis, S. graminifolia, etc. 
VII. Zone of marginal willows.—Salix nigra, S. lucida, S. dis- 
