1907] Fernald,— Soil Preferences of Alpine Plants 187 
7 “Scattered on the hills and plains [near North Bluff, Hudson Strait], were several 
[boulders] of grey dolomite....and of the soft buff grey dolomite."— Bell, 1. c. 22 DD. 
“On the west side of Ashe’s Inlet....some of them [veins] contain feldspar and black 
mica, [magnesian]."— Bell, 1. c. 29 DD. “At Ashe's Inlet a party of Eskimo from the 
eastward came on board." Among the rocks shown them “they recognized a rather 
hard and inferior variety of soapstone,"— Bell, 1. c. 21, 24, 25 D D. 
8 ' At a projecting point....I found some straggling veins of hard grey dolomite."— 
Bell, 1 c. 29 D D. 
It is not, of course, possible from the inadequate data at hand to 
say with certainty that in their arctic and subarctic distribution in 
British America the fifteen plants just discussed are confined to or 
even occur upon the soils which have respectively a preponderance 
of potassium, calcium, or magnesium; but it is clear that in the north- 
ern regions from which these plants are known soils are present similar 
to those upon which the plants have their best development south of 
the St. Lawrence. In their southern stations, however, it is apparent 
that the plants of alpine situations here considered show in most cases 
a pronounced selection of habitats dependent upon the relative abun- 
dance in the soil of the three important food-elements, potassium, 
calcium, and magnesium. A very similar selection of soils is shown 
by many plants of low altitudes; in fact, it is possible thus to analyze 
the distribution of the majority of Pteridophyta and Spermatophyta 
of New England and eastern Canada. It is very generally known, 
for instance, that. many heaths (Kalmia, Rhododendron, Vaccinium, 
ete.) occur primarily on potassic soils; and that they are rare or quite 
unknown in extensive areas of limestone and can there be cultivated 
with success only if provided with an imported soil free from the 
abundant lime of the region. Many other plants of low altitudes or 
of temperate regions, Camptosorus rhizophyllus, Pellaea atropurpurea, 
Carex eburnea, etc., are best developed on if not confined to calcareous 
rocks. These plants of low altitudes, Kalmia latifolia, Rhododendron 
canadense (Rhodora), R. maximum, Vaccinium pennsylvanicum, Camp- 
tosorus, Pellaea atropurpurea, Carex eburnea, etc., restricted in their 
best development to somewhat specialized soils and ordinarily absent 
1" Any open, well-drained soil which does not contain limestone or heavy clay and 
has a moist and fresh subsoil will prove satisfactory [for Rhododendrons]. Where 
limestone or heavy clay prevails, beds must be specially prepared and filled with suitable 
soil."— A. Rehder, in Bailey, Cycl. Am. Hort. 1516, 1517 (1902). 
"It is generally conceded that lime soils and manures containing lime .... are 
injurious to Rhododendrons; in limestone regions it is undoubtedly advisable to sub- 
stitute, for the natural soil, others which are free from this objectionable element."— B. 
M. Watson in Bailey, l. c. 1519. 
