1907] Fernald,— Soil Preferences of Alpine Plants 175 
potassic rocks, a few are able to grow, under protest as it were, upon 
the strongly magnesian soil of Mt. Albert; but that another group of 
plants, unknown upon our granitic, gneissic, and schistose mountains 
or on the strongly calcareous mountains and cliffs,.are not only re- 
stricted to the strongly magnesian rocks, but there attain a normal 
and often a luxuriant development.! 
It will be remembered that on the northern edge of Mt. Albert 
(Group Ia) two groups of plants are found; some species ordinarily 
confined to the potassic rocks (feldspathic or micaceous), others gen- 
erally known only from the strongly calcareous soils. Different sec- 
tions of the northern and eastern slopes of the mountain examined 
by Mr. Low showed the rock of the upper or subalpine and alpine 
district to be chiefly hornblende-schist and amphibolite, with occa- 
sional large areas of impure limestone, chloritic slates and schists; and 
gneiss, made up chiefly of orthoclase (potash-feldspar) and hornblende ? 
and as indicated by rock-specimens kindly examined microscopically 
vias be Porte in view of the great abundance on the serpentine of Mt. Albert of 
e 
places on the serpentine hills, and in no other parts of hee Island’’; and that an analysis 
of the ash of the =e Island plant showed it to con 
“Silica (Si0,) ; / . 39.85 
Alumina and Oxide of Iron (Al, oO, and Fe 0») : : . 18.58 
ria bina ) 2 j ne 
a (MgO) 19.79” 
See Seg & page tebe Bull. Tor IT. cl. xiv. "45-50 (188 7). 
This is a remarkable — of magnesia to be present in a plant, the average plants 
of mixed soils vipa fen fro: Be: hat ae less magnesia (See Dana, Man. ed. 4, 74). 
As ale are in Maine, only one atation, on the rocks 
between Cape pvt and dig regen gine t Cape Elizabeth, being known personally 
to the writer; and, according t F ik ‘Cape Elizabeth is largely co fudaei of 
talcose schist [hydrous silicate of seit ium] ”- 7 C.H 1. Hitchcock, Agr. and — Me., 
Ser, 2, 1861, e 162 (1861). It ‘erastium 
arvense is entered in Group I only — the eastern coast of Maine. _ The stations are 
few, the odie Islands, ete., and it 
si for Hitchcock records paoaneg pe and serpentine as “largely present alon ng the 
Coast of Penobscot Bay and on some of the neighboring islands, (Hitchcock, 1. c., 
162-163). 
Several other plants of low eg have = recorded as occurring primarily on 
sia: i] ob m 4 le ae ans : pl cok eae + 5 
In n Europe, two much-discussed ferns, Asplenium adulterinum Milde and A, Adiantu 
nigrum, subs int (Tausch) Heufier, are clearly demonstrated to grow ae ia on 
serpentine, and on that rock to take the places respectively of A. viride, which prefers 
calcareous rocks, = A. Adiantum nigrum (typical), which is commonly on silicious soils. 
—For discussion see Luerssen, Farnpfi. 165-184, 275-281 (1889), also Schimper, Pflanzen- 
— 103, i it (808). 
1. Surv. Can., Rep, for 1882-83-84, pt. F. 17, 18 (1884). 
