Fe TRANSEAU—BOGS OF THE HURON RIVER VALLEY 447 
" Prunus serotina, Quercus alba, Q. macrocarpa, Acer rubrum, Betula 
litea, Amelanchier Botryapium, Viburnum pubescens, Spiraea 
wlcifolia, S. tomentosa, Corylus americana, Sambucus pubens, 
Comus candidissima, C. stolonifera, Cicuta maculata, Aster lateri- 
orus, Carduus altissimus, Galium asprellum, Osmunda cinnamomea, 
0, regalis, Ranunculus pennsylvanicus, Calamagrostis canadensis, 
Viola blanda, Euthamia graminifolia, Bidens frondosa, and Aster 
Novae-Angliae. 
__ Sedge society.—On the northeast side of the bog is an area domi- 
_ fated by sedges. In the fall of the year it appears to be a uniform 
atta of Scirpus cyperinus, but there are many other species mixed 
with it. The substratum is low and is mainly characterized by 
lissocks formed by the sedges. Throughout, occur small clumps 
if the willows already mentioned. The most abundant accessory 
species are Isnardia palustris, Calamagrostis canadensis, Carex 
_ letiuscula, C. stipata, C. filiformis, C. fusca, C. oligosperma, 
C riparia, and Aulacomnium palustris. 
The future flora of this bog appears to be indicated by the rapid 
fowth of the poplars, willows, and oaks. The few tamaracks 
tMaining are approaching maturity and are not being reproduced, 
~ The means by which these tree species combat the shrubs is mainly 
oy shading, while the latter in the same way interfere with the develop- 
~ Ihent of the tree-seedlings. The time involved in this struggle must 
| be very great, but the ultimate outcome will be an oak forest, the 
intervening Stages being filled in by poplar and willow growths. If, 
_“Wever, the decay of the peat beneath these trees brings the surface 
ia water level, the poplar-willow stage will be indefinitely pro- 
onged, 
GENERAL CONSIDERATION OF THE BOG FLORA. 
Beside the trees mentioned in the preceding descriptions, aie 
should be made of the occasional occurrence of the black ash, Fraxinus 
tigra, and swamp white oak, Quercus platanoides, in bog areas. It 
"quently happens, when the tamaracks are cut, that the black ash 
mes abundant, as in the area one-half mile southeast of Kava- 
augh Lake, where it is now associated with Ulmus americana and 
Acer Tubrum. Another example occurs about a mile north of Chelsea 
7 te NE. % Sec. 1, Sylvan Tp. Here in a small area from which 
& lamaracks were removed, Fraxinus nigra, Quercus platanoides, 
