480 Part IV. Chapter 2. 
orum. On Slide Mountain at an elevation of 3,500 feet on cliffs and ledges among the balsams 
= balsamea were collected, such mosses as Raphidostegium Jamesii, R. laxepatulum, Plagio- 
theeium striatellum (= Hypnum Muhlenbeckii), P. Muellerianum, Hylocomium umbratum, H. pyrenai- 
cum (= Hypnum Oakesii), Dieranum fuscescens and D. longifolium. 
This balsam facies, according to my observations, covers the highest 
mountain peaks in the Catskills viz., Wittenberg (3,824 feet), Cornell 
(3,920 feet), Table Mountain (3,875 feet) and Slide Mountain (the highest dome, 
4,200 feet). It extends down the mountain slopes in tongues into the deciduous 
forest below and at the lower elevations it breaks up into isolated patches 
easily delimited by the dark green color of such patches in a lighter green 
background. Its constitution is very similar to the topmost plant forma- 
tions of the Adirondacks, and the mountains in Virginia, North Carolina 
and Tennessee. 
In the mountainous parts of Pennsylvania we find an other arrange- 
ment of the Coniferous Forest Formation as follows’). 
Pinus Strobus Facies. The dominant tree Pinus Strobus associated 
with Picea nigra (= P. mariana) formed on the higher tablelands of the northern 
Appalachian area an almost pure forest under which grew Sordus americana, 
Acer pennsylvanicum, Ribes lacustre, R. prostratum and Rhododendron maxi- 
mum. A magnificent growth of white pine once covered the slopes of the moun- 
tains and the sides of the ravines, overshadowing and enclosing the smaller 
streams, and attaining its best development about their headwaters. In the 
deep ravines it was usually associated with the hemlock Tsuga canadensis, 
Betula lutea, Castanea americana, Acer rubrum with an occasional Fraxinus 
americana and rarely Liriodendron tulipifera. It spread completely over many 
of the mountains growing in mixture with hemlock or making pure stands. At 
the top of the slopes, and upon the summits of the mountains on poor soil, 
Pinus rigida usually takes its place. The white pine in western Maryland 
occurs almost entirely on northern and eastern slopes, ascending to the summits 
of the highest mountains. It is especially abundant along the rocky north 
slopes of streams, often forming dense narrow belts of pure growth down to 
the water’s edge. 
Tsuga Facies (see plate XIb at p. 465). The hemlock is an element 
of tbe mountain flora. As a tree, it prefers the rocky sides of mountain 
gorges, or a rocky hillside overlooking a stream. Occasionally it appears in 
a deep forest on flat ground by a stream. Ik is very scarce along the southern 
border of the state, except in the mountains proper. It is frequently associated 
with the white pine and the association of species is much like that in the 
white pine forest only a few plants become more prominent among them 
such herbs on the ground as Viola rotundifolia, Mitchella repens, Goodyera 
pubescens, G. repens, Spiranthes gracılis, Cypripedium acaule. 
1) Consult SARGENT, CHARLES $.: Report on the Forests of North America. Tenth U. S. 
Census Vol. IX. 1880 pages 506—510 with map, 
