1905] TRANSEAU—BOGS OF THE HURON RIVER VALLEY 437 
myrtilloides are the most frequent plants. The accessory species. 
include Carex oligosperma, Menyanthes trifoliata, Comarum palustre, 
Tnadenum virginicum, Osmunda regalis, Onoclea sensibilis, Rumex 
Britannica, Asclepias incarnata, Viola blanda, Cicuta bulbifera, 
Galium Aparine, Scutellaria galericulata, Rhus Vernix, Dulichium 
aundinaceum, Oxycoccus 
macrocarpus, Hypnum 
cordifolium, Hypnum 
Schreberi, Aulacomnium 
palustre, and Mnium. 
Vaccinium-aronia society. 
—Forming a narrow tran- 
sition society between the 
low shrub zone just de- 
scribed and the tree society, 
occurs a dense line of tall 
shrubs. The dominant 
species are Vaccinium cor- 
ybosum, Gaylussacia re- 
‘tosa, Aronia nigra, Ilici- 
dides mucronata, Betula 
dulosa, and Prunus | 2. 
Srotina. The other species“ pear rss SE 
Present are Acer rubrum, Fic. 8.—Portion of Delhi bog. 
Sambucus pubens, Os- ee 
munda cinnamomea, Salix discolor, $. Bebbiana, Spiraea salicifolia, 
Tlex Verticillata, Rosa Carolina, Sarracenia purpurea, Andromeda 
lifolia, Calamagrostis canadensis, and Eleocharis palustris sei 
ns. These shrubs border the tamaracks and to varying distances 
_-&xtend back among them. 
Tamarack-birch society.—Larix laricina and Betula lutea — 
ve made up the great bulk of the original forest which occupied 
_ > area. The relative abundance of the latter has probably been 
“teased by the cutting of the tamarack. The next most ienportant 
tree is Acer rubrum, which occurs scattered throughout, apd 
“ally abundant near the northeast side. Where isolated trees have 
Temoved, the shrubs which occur among the undergrowth have 
