1905] TRANSEAU—BOGS OF THE HURON RIVER VALLEY 435 
Poplar-willow-ma ple society.—Where the original conditions have 
been disturbed and a second growth allowed to come in, Populus 
iremuloides, Salix sericea, Salix discolor, and Acer rubrum have 
obtained dominance. Where groups of the more mature poplars 
ocur there is scarcely any undergrowth. Elsewhere the following 
plants occur: Ilicioides mucronata, Salix Bebbiana, Sambucus 
pubens, Amelanchier oligocarpa, Aronia nigra, Rubus nigrobaccus, 
Comus. stolonifera, and Rubus strigosus. These form a dense mixed 
association, with but slight reference to substratum conditions. T he 
smaller species present are Adicea pumila, Osmunda cinnamomea, 
Rosa Carolina, Onoclea sensibilis, Epilobium adenocaulon, Spiraea 
salicifolia, Dryopteris thelypteris, Verbena hastata, Solanum dul- 
tamara, Polygonum sagittatum, Spiraea tomentosa, Geum rivale, . 
Polygonum hydropiperoides, Ribes floridum, Ribes oxyacanthoides, 
Rumex Britannica, Impatiens biflora, Viola blanda, Osmunda 
Tegalis, 
On the southeast side of the lake and on the north, conditions 
have been still more interfered with, and there is now a mixed growth 
of bog and low-ground plants, which represent stages in the decline 
of the bog flora and the advent of swamp plants. The tallest forms 
ate willows and clumps of mountain holly. For convenience only, 
the plants may be enumerated together under the following title: 
Mt ixed low-ground society.—The dominant plants are Salix 
“ticea, S. discolor, Spiraea salicifolia, Poa flava, Solidago serotina, 
Chamaedaphne calyculata, Oxycoccus macrocarpus, Aster Vide 
gliae, and Rosa Carolina, Epilobium adenocaulon, Aronia nigra, 
Andromeda polifolia, Rubus strigosus, Dryopteris thelypteris, 
Scutellaria galericulata, Juncus effusus, Koellia virginiana, Sambucus 
‘anadensis, Geum rivale, Osmunda regalis, Scirpus cee’ 
Gali um aparine, Homalocenchrus oryzoides, Juncus tenuis, Asclepias 
_ittarnata, Salix Bebbiana, Eupatorium perfoliatum, Gentiana 
Et, Lycopus virginicus, Osmunda cinnamoméa, Saat 
nifera, Carex riparia, Viola blanda, Sarracenia pe 
Yopteris cristata, D. spinulosa intermedia, and Triadenum vit- 
siticum also occur. 
oe last two societies are found upon a black peat 
1S more thoroughly decayed than in other parts 
substratum 
of the bog. 
