1904 | WELD: BOTANICAL SURVEY OF HURON VALLEY 43 
dently from seeds that have floated to the places where they are 
growing. Others grow further back, among which are the cran- 
berry, buck-bean, white violet, and sphagnum. Following is a 
list of the plants of this zone, as far as determined, somewhat in 
the order of their relative importance and abundance. 
Carex filiformis, Glyceria nervata, Eleocharis palustris, Aspidium nove- 
boracense, Viola blanda, Menyanthes trifoliata, Potentilla palustris, Equise- 
tum limosum, on east side near edge of water, Vaccinium Oxycoccus on 
S. E. and N. W., Carex four species, Onoclea sensibilis, Osmunda regalis, 
Asclepias incarnata, Dulichium spathaceum, Eupatorium perfoliatum, 
Mentha canadensis, many seedlings of Bidens and Impatiens in spring, Cas- 
sandra calyculata, Salix myrtilloides, Eriophorum gracile, Scutellaria galeri- 
culata, Campanula aparinoides. 
At the north end of the lake, in a particularly soft place, is a 
patch of Zypha latifolia, but elsewhere there is a sharp transition 
between lilies and sedges, the Pontederia and Typha zones as 
commonly represented being wanting at this lake. 
4. Cassandra zone. This zone is characterized by an advance 
of shrubs, of which cassandra is the most conspicuous. This, 
with the accompanying sphagnum, is active in raising the marsh 
and preparing it for tree growth (fig. 4). It is not present in all 
cases, but when present the succeeding forest floor is much drier. 
Its development here is weak. It is accompanied by Andro- 
meda, chokeberry, small willows, huckleberry, low birch, and 
mountain holly. Around some lakes east of Whitmore this zone 
of shrubs is much better developed, consisting, however, of wil- 
lows as dominant species, with no cassandra. 
The plants of this zone at the first lake include: Cassandra calyculata, 
Sphagnum sp., Andromeda polifolia, Pyrus arbutifolia melanocarpa, Nemo- 
panthes fascicularis, Gaylussacia resinosa, Salix myrtilloides, Viola blanda, 
Rumex Acetosella in the drier spots, Lycopus lucidus americanus, Glyceria 
nervata, Aspidium noveboracense, Osmunda cinnamomea, Solidago sp., Sar- 
racenia purpurea growing half hidden in the sphagnum at the base of the 
clumps of cassandra, Drosera rotundifolia between clumps of cassandra 
with sphagnum and: buck-bean at the northwest side of the lake, Arethusa 
bulbosa growing in the sphagnum, Habenaria lacera, Pogonia ophiogloss- 
oides, Calopogon pulchellus, Menyanthes trifoliata. 
We are still at a loss to explain the distribution of these bog 
plants, particularly the orchids. 
