Lake Distriet: Adirondack Mountains. 405 
of tolerance beginning with those that require the most light: Larix americana, Populus tremuloides, 
Prunus pennsylvanica, Pinus Strobus, Betula lutea, Acer rubrum, Abies balsamea, Picea rubra, 
Tsuga, Fagus and Acer saccharum. The species in general may be arranged according to edaphic 
requirements beginning with the most requiring: Prunus serotina, Acer saccharum, Fagus americana, 
Acer rubrum, Pinus strobus, Abies balsamea and Picea rubra. — As one ascends, the associations 
in some places consists of the deciduous species mentioned with Adiantum pedatum, Polystichum 
acrostichoides, Monotropa uniflora, Chiogenes hispidula, Clintonia borealis, Cornus canadensis, 
Panicularia elongata on the ground below. 
Coniferous forest Formation. At 3,600 feet (below ı200 m) especially on 
the southern flanks of Mt. Tahawus the coniferous forest formation consists of 
Picea rubra with Betula lutea, lenta and Sorbus americana. Abies balsamea, 
Thuja occidentalis and Veratrum viride occurs on the forest floor, with Vaceı- 
nium canadense, Lycopodium annotinum and lucidulum, Aster acuminatus, Soli- 
dago flexicaulis, Coptis, Linnaca, Streptopus amplexifolius. These southern 
slopes are the spruce slopes, according to the designation of lumbermen, 
because Picea rubra is prominent. The absence of any Acer and Vidurnum 
lantanoides is due to elevation and is noteworthy. Adies balsamea on an ele- 
vated saddle of the mountain forms a pure association with shrubby and herba- 
ceous companions (Abies-Facies), and in open swampy places surrounded 
by the balsam occur Osmunda cinnamomea and Veratrum viride. The hemlock 
Tsuga canadensis forms pure associations (Tsuga-Facies), as on the ridges 
at the foot of Giant Mountain. Here the beech and the maples (Acer) are 
subordinate species with a few spruce trees (Picea) intermixed. 
The herbaceous undergrowth is typie of such forests consisting of Linnaea borealis in mats, 
Mitchella repens in mats, Cornus canadensis in patches, Pyrola chlorantha, Ozalis acetosella, 
Clintonia borealis, Goodyera (Peramium) repens, Medeola virginica, Pyrola secunda, Viola suekange 
olia, Chimaphila umbellata, Gaultheria procumbens, Coptis trifolia , NERSRHED TRAUM (Uuifolaeh) 
i Habenaria (Lysias) orbieulata, Lycopodium lucidulum. This is the 
one finds in southern Pennsylvania with the 
Clintonia borealis, Coptis trifolia. 
In more elevated situations, the botanist finds on Giant Mountain a Picea- 
Abies-Facies, associated with three birches, Acer rubrum, Ribes prostratum, 
Rubus strigosus, and with a few ferns (Dicksonza punctilobula!) abundant. = 
Pinus resinosa in a few localities, as on the southwest slopes of Baxter Mountain 
(2,400 feet = 732 m), forms an association (Pinus resinosa-Facies) sometimes 
with Zinus strobus interjected; Funsperus communis together with Vaccınıum 
Dennsylvanicum and V. canadense, Pteris aquilina form an association on rocks 
(Juniperus-Vaccinium-Association). The > pines dominate the Pa 
west slopes of Mt. Baxter down to the lowest ridges ‚where Quercus rubra, 
Acer pennsylvanicum and Tsuga canadensis are in association. 
2. Alpine Summits, Bogs and Rocks. 
The Krummholz or dwarf timber (Dwarf Tree Formation) is reached at 
5,000 feet (1,530 m) on Mt. Tahawus. Here Abies balsamea is about five feet 
high with its base covered by Hypnum splendens, crista-castrensis, Dicranum 
