1907] Fernald,— Soil Preferences of Alpine Plants 171 
var. nana, for example, seem equally at home in crevices of sun-baked 
or spray-showered rock, on sandy plains, in well-drained alpine mead- 
ows, and in saturated sphagnum bogs. With our alpine plants so 
ubiquitous, then, in their occurrence, upon saturated, well-drained, or 
dry soils, and with an apparent ability to thrive equally well in fine 
river alluvium or in the crevices of a scarcely altered ledge or cliff, we 
are hardly justified in depending upon these factors to explain the 
distribution indicated in the preceding tabulation. 
When, on the other hand, we examine the lithological character of 
the regions in which these plants occur we find a very striking coinci- 
dence between the soil-forming rocks of these mountains and cliffs 
and the distribution of the plants which cover them. 
In the first group of alpine areas specially indicated — the great 
mass of the White Mountains of New Hampshire; the Adirondack 
Mountains of New York; the highest summits of the Green Moun- 
tains of Vermont; Baldpate, Saddleback, Abraham, Bigelow, Katah- 
din, and nearly all the other naked-topped mountains of Maine; the 
great tableland of Table-top Mountain in Gaspé; and Mt. Desert 
Island and other parts of the exposed eastern coast of Maine — the 
predominant and often the exclusive rocks are granite or gneiss (both 
containing much orthoclase or potash-feldspar, and generally musco- 
vite or potash-mica) or mica (muscovite)-schist,' often in close proxi- 
mity, and all especially high in potassium. "The distinctive soil ele- 
ment of the alpine areas constituting Group I is, then, potassium; 
and on these mountains and cliffs peculiarly rich in potassie constitu- 
ents we find 122 of the plants here discussed, nearly two-thirds of 
which in their alpine distribution are quite unknown on the moun- 
tains of Groups II and III. 
When, however, we examine the second large group of alpine and 
subalpine areas we shall find that their characteristie rocks differ 
from those of the first group — the mountains characterized by 
granite, gneiss, and mica-schist, rocks which furnished a strongly 
potassic soil — in one constant point. The cliffs of Percé, of the 
1 For valuable assistance in the determination of several characteristic rock-specimens 
from eastern Quebec the writer is under special obligations to Professor J. E. Wolff and 
his student, Mr. H. N. Eaton, Upon these determinations and the detailed reports of 
members of the Geological Survey of Canada the writer has chiefly depended for the 
lithological data in this article. He is also indebted for suggestions upon the soil con- 
stituents of many rocks to Mr. H. H. Bartlett of the Gray Herbarium. 
? For details of the mountains and cliffs of Percé see J. M. Clarke, N. Y. State Mus., 
Rep. lvii, 1. pt. 1 (Bull. 80), 133-171 (1905). 
