Northern Appalachian District. 479 
he shrubby undergrowth consists of Sorbus americana, Rhus hirta, R. copallina, Aralia 
Sr and Kalmia latifolia on the drier soils; along streams Asimina triloba, Hamamelis vir- 
iniana, Pirus coronaria, Amelanchier canadensis, Crataegus coccinea, Cercis canadensis, Cornus 
iii Acer pennsylvanicum and spicatum are found on the steep river slopes and Rhodo- 
endron maximum and Viburnum lentago in the swamps. 
The un. .. of such forests as they occur in ‚wen Virginia are mentioned below; 
Trautvetteria p a, occurs along deeply shaded mou an ‚all; Aconitum uncinatum grows 
along banks of rivers, while Actaea alba and A. rubra uns Cim cifuga racemosa are on the at: 
mountains. Dicentra eximia is also at high elevations. dien lueidulum, L. annotinum, L. den 
droideum, L. clavatum and L. complanatum are all found in the forests of Picea nigra along the 
mountains at 2,500—4,800 feet in altitude with Abies balsamea and Pinus Strobus, 
Coniferous Forest Formation. These exist in the Catskill Mountains in 
three types determined by the dominant tree of each type. They are the 
Tsuga-facies, Strobus-facies and Abies balsamea-facies. 
suga Facies. Formerly the hemlock, Tsuga canadensis, grew in 
considerable abundance in the Catskill Mountains. It formed pure growths 
along the steep slopes of mountain streams, or on the northern shaded shoulders 
of ridges descending into the principal valleys. It was much sought as a bark 
and timber producing tree and much of the best hemlock has beeg removed 
long since from the Catskill forest. One isolated grove in Big Indian Valley 
was studied by the writer, and it may be taken as a type of the original 
hemlock formation. T7Suga canadensis is the dominant tree associated with 
Fagus americana, Acer rubrum, A. saccharum and Betula lutea, which are 
sparingly present in this type of forest. On the ground the botaniat finds 
Mitchella repens, Viola rotundifolia, Lycopodium lucidulum, Chimaphıla um- 
bellata, etc. while Kalmia latifolia forms the shrubby undergrowth. 
Pinus Strobus Facies. This at present is found in a few localities and 
it represents largely a second growth in the wider valleys not at any con- 
siderable elevation. As a formation, it occurs surrounded by the deciduous 
forest on the sunny lower slopes of mountains, exposed to the noonday sun. 
The white pine is the dominant tree in pure growth, while beneath the pines 
one finds much the same association of species as in the hemlock formation, 
such as, Gaultheria procumbens, Chimaphila umbellata and Pirola rotundifolia. 
Abies balsamea Facies. Above 3,200—3,500 feet on the higher moun- 
tains, such as, Cornell, Wittenberg, Slide mountains the balsam, forms an 
almost pure growth, Asbociated with Picea nigra, Sorbus americana, Betula 
lutea, Prunus pennsylvania and Acer pennsylvanicum, while the undergrowth of 
shrubs consists of Viburnum lantanoides, Ribes prostratum, Sambucus racemosa, 
Rubus odoratus (at lower elevations). 
The herbs of this forest formation are Dennstaedtia punctilobula, Oxalis BREI Circaea al- 
pina, Viola blanda, Clintonia borealis, Mitchella repens, Cornus canadensis, Coptis llorhiza 
Fame Lycopodium lucidulum and on the m mi windfalls Cladonia rangiferina with Chiogenes 
ispidula. On the tops of the larges st boulders occur in dense mats Polypodium vulgare and on 
ar sides species of the lichen Umbilicaria. Tardlahie pennsylvanicum found in this formation 
arising from a ımhossy bed beneath the balsams. is a shrub from a foot to two feet high and at 
the lower elevations in this formation are found Rhododendron (Azalea) viscosum and R, nudi- 
