The Alpine Flora

Abstract

MR. THISELTON-DYER, in his interesting letter in NATURE (p. 581), does not mention one of the striking characteristics of the Alpine flora—the remarkable brilliancy of the flowers, as compared with those borne by the same or similar species in England. A comparison of this kind made by the memory is no doubt not severely scientific, but those tourists in Switzerland who are in the habit of observing flowers will probably confirm the statement. Plants grown at high levels in the Alps are, as Mr. Dyer says, above a great screen of aqueous vapour, and I have in my own mind always put down the greater brilliance of Alpine flowers to their getting more sun than in our cloudier climate. It is not, however, solely any alteration in the actual effects of the solar rays, caused by this absence of aqueous vapour, that makes the colours of Swiss flowers so bright. The same, or, I should assert from memory, even greater, brilliancy, will be found in Arctic and sub-Arctic Norway by anyone who visits the Throndhjem district and the coast to Hammerfest in June. Western Norway notoriously is one of the moistest parts of Europe; but, on the other hand, it has, broadly speaking, no night at midsummer. It is thus apparently the quantity, and not the quality, of the sunlight that causes the peculiarly vivid colours of Swiss flowers, including those of the pastures from 2000 feet upwards. I have never been in Switzerland in spring, and I cannot therefore judge whether the colours of the flora in the lower districts are also more brilliant than ours; but it will be seen below that Swiss observers find that the high Alpine flora is much more brilliant than the same plants in the lowlands.