Alpine flora

“ The stronghold of this last, the distinctively “Alpine” flora, is the region above the tree-limit. Its closest relationship is with the flora of the Pyrenees; but an alpine flora is characteristic of all the lofty mountains of central Europe. According to J. Ball, 2010 well-marked species of flowering plants occur within the limits of the Alps. ”

“ In Europe they chiefly occur in Scandinavia and the central and southern mountain ranges, whilst they are mostly absent from the intervening lowlands. Again, we find a large number of species in the mountains of Central Asia and in some of the North American mountains. Almost all species of Alpine plants, in fact, are examples of discontinuous distribution; and this, as every naturalist knows, is always, in both animals and plants, a proof of antiquity.
The glacial or Alpine flora is very old, and must have originated long before the Ice Age. ”

“ They can never, of course, get very far away from the regions skirted by eternal frost, for their cup of joy must be chaliced by the snow-flake, or their beautiful life is soon ended. But if all our alpine flora have traveled from one evolutional centre, or have been "created but once in time and place," how have they managed to cross the thermal equator and spread themselves out over all the alpine regions of the globe? We call upon Mr. Darwin and Professor Gray to rise and explain. Not that we want any explanation, but that their theory of plant-migration stands sadly in need of one. ”

“ The alpine floras of Europe and Asia, so far as they are identical with the flora of the Arctic and sub-Arctic zones of the Old World, are fragments of a flora which was diffused from the north, either by means of transport not now in action on the temperate coasts of Europe, or over continuous land which no longer exists. The deep-sea fauna is in like manner a fragment of the general glacial fauna. ”

“ Something of the nature of the gorgeous fields of bloom about the great peaks of the Pacific mountains is suggested on the treeless summits of the White Mountains, but although classed by botanists among alpine floras, the plants growing there fail to give a true idea of the display characteristic of the mountains which make a nearer approach to the lower limit of perennial snow. In the southern Appalachians the absence of a luxuriant alpine flora is perhaps more than counterbalanced by the profusion of rhododendrons, azaleas, and laurels. ”

“ With the advent of a milder temperature the Arctic vegetation has gradually disappeared from the plains. Driven up step by step before the advancing flora from more genial climates, it retired into the mountains and there to this day continues to maintain itself. The present Alpine flora of the Pyrenees, the Alps, Britain, and Scandinavia, is thus a living record of the ice age. The reindeer and his friends have long since been forced to return to their northern homes.
After this long succession of physical revolutions, man appears as a denizen of the Europe thus prepared for him. ”

“ Especially ought we to discover important facts bearing upon the soundness of the propositions respecting the origin of our alpine flora, for we have already seen that the conversion from a general flora, clothing most parts of the area as were then above water, into a limited assemblage of plants almost all confined to the mountain summits, was owing to an elevatory action by which the bed, or a great part of the bed of the glacial sea, was left high and dry. ”

“ Due consideration in this interesting speculation, however, is not given to the fact which he himself emphasised, that Alpine plants are particularly prone to suffer from a dry climate. Even a moderately dry cold [Pg 345] kills most of them. How can we then reconcile this fact with the theory of their origin in a dry and intensely cold climate? I quite agree with the views as to the Asiatic origin of the bulk of the Alpine flora, while the dry state of the Siberian climate is certainly indicated by the extremely feeble development of the glaciers during a large part of the Glacial period. ”

“ But they hare also in a most surprising manner confirmed another supposition, namely, that which considers our Alpine flora to have had its origin in the far north. Not only all the species which have as yet been found in the glacier mud have their home in the north, but amongst them is found the polar willow, which at the present day is only found in the Arctic zone (in North Lapland and Spitzbergen) , but it is entirely wanting in the Alps. So that this species has come from the north into our districts, but here became extinct ”

“ Like these the tarns were surrounded by an Alpine flora, the remains of which fell into the mud, and have been preserved to our own days. . . . In the 'Urwelt der Schweiz,' p. 534, &c., I have endeavoured to show that at the Glacial age the Alpine flora very probably occupied the plain land of Switzerland, so far as it was free from glaciers, and that the Alpine plants which we now see insulated on the mountain chains of Northern Switzerland may be the last remains of this ancient flora—the lost children of the Alps surrounded entirely by the inhabitants of the plain. ”

“ When the climate of the intervening districts became once more less severe, the competition with the present lowland flora became so keen that the Alpine-Arctic plants retreated to high altitudes or the far north. It may be that the high mountain regions have formed centres for the evolution of new species, as Mr John Ball believed, but there is but little direct evidence for this view.
Nearly every visitor to Switzerland who regards its rich flora in any way worthy of notice is desirous to obtain some permanent record of the pleasing impressions obtained. ”

“ The Alpine Flora.
The Alpine Flora, of which in a preceding section we have given a very imperfect sketch, has been examined with loving minuteness by Messrs Elijah Walton and T. G. Bonney; and other united results of pen and pencil have been placed before the public in a handsome volume entitled "Flowers [418] from the Upper Alps, with Glimpses of their Homes." A somewhat similar subject has been treated with much delicacy of feeling and fervour of description by the Rev. Hugh Macmillan, in his "Holidays in High Lands." ”

“ Arctic. On our loftier hills, indeed, the heat is on occasions oppressive.
Again, the mountain climate, with its heavy rainfall and long cold period, tends to the formation of peat; and the acids thus engendered in the soil, as well as the low temperature prevailing during most of the year, render difficult the absorption of water by the roots of plants. The conditions under which alpine plants, then, live may be summed up as follows: a long cold winter, a short summer; great exposure; scarcity of food-supply. ”

“ The brief summer and long winter are unsuitable to the economy of annual plants; and the alpine perennials are so constructed that with the passing away of the cold, flowering and fruiting may be accomplished quickly, before winter descends again. The abundance and vividness of the flowers of alpines is almost proverbial. ”

“ The shrubs of the alpine zone are mostly small and creeping, weaving themselves among the vegetation, and with low grasses and sedges forming a mat which is equally resistant to all inimical conditions. Their leaves are small, to avoid damage by wind or by excessive transpiration. In some genera—for instance, Veronica—the diminution of leaf surface accompanying more elevated habitat is very striking. ”

“ For now that we know the vast area swept by the glacial sea, including almost the whole of central and northern Europe, and belted by land, since greatly uplifted, which then presented to the water's edge those climatal conditions for which a subarctic flora—destined to become Alpine—was specially organized, the difficulty of deriving such a flora from its parent north, and of diffusing it over the snowy hills bounding this glacial ocean, vanishes, and the presence of identical species at such distant points remains no longer a mystery. ”

“ There is no true alpine flora on the higher summits, but several of the temperate forms extend to a great elevation. Thus Mr. Pickering records Vaccinium, Ranunculus, Silene, Gnaphalium and Geranium, as occurring above ten {324}thousand feet elevation; while Viola, Drosera, Acæna, Lobelia, Edwardsia, Dodonæa, Lycopodium, and many Compositæ, range above six thousand feet. Vaccinium and Silene are very interesting, as they are almost peculiar to the North Temperate zone; while many plants allied to Antarctic species are found in the bogs of the high plateaux. ”

“ Round the lakes at the base of the steep southern slope of the Alps, Mediterranean forms of vegetation appear; the chestnut reaches up to two thousand five hundred feet; above that comes the belt of beeches and oaks, still higher the pine woods, then the pretty alpine plants and high pastures. Scarcely any part of the world is so covered with irrigating canals as the highly cultivated plain of Lombardy, so that the whole of it appears like a great garden. At the northern base of the Apennines the Mediterranean flora of laurels and myrtles, cork oak and cypress, covers the first slopes ”

“ As all living organisms are greatly influenced by their environment, the flora naturally distributes itself along the lines of climatic variation. Thus we have alpine species on the snowy heights of the Sierras, and sub-alpine forms luxuriating in the meadows fed from their snows; inland species in the Central Valley, and following some distance up its eastern and western walls; the leathery and hardy forms of the wind-swept coast; the curious prickly races of arid regions; delicate lovers of the cool and shaded brook; dwellers in marshes and on lake borders ”

“ In the upper or Alpine zone, on the contrary, night frosts recur not unfrequently throughout the year, snow falls from time to time, more frequent in winter—from May to August—but does not lie long enough to provide a season of complete rest to the vegetative organs. To the influence of these conditions we may104 probably attribute the chief characteristics of the flora. With scarcely an exception, the species of this zone are stunted in growth, rising but a few inches from the surface, but have much developed prostrate or creeping woody stems, or underground rhizomes. ”

“ As the height of the snow-line varies according to the latitude and local conditions, so also does the height at which these plants grow. The mean height for the alpine plants of Central Europe is about 6000 feet; but it rises in parts of the Alps and in the Pyrenees to 9000 feet, or even more. The high grounds clear of snow among these mountains present a very well marked flora, the general characters of the plants being a low dwarfish habit, a tendency to form thick turfs, stems partly or wholly woody, and large brilliantly-coloured and often very sweet-smelling flowers. ”

“ This cushion form has many advantages for the alpine plant. It keeps it warm in winter and cool and damp in summer; it allows it to produce a great amount of blossom without the necessity for extensive growth; it resists the utmost efforts of furious gusts of wind almost as well as would a half-buried stone ”

“ But it is in connection with their flowers that the wonderful adaptation of Alpine plants to their surroundings is perhaps best seen. The plants of high altitudes generally bear more numerous and more brightly coloured flowers than do their relatives of the plains. The low stature of the plants that bear them gives rise to the impression that the flowers of the Alps are also larger than those of lowland districts, but though undoubtedly more numerous and more crowded together they are of about the same size as those of other nearly related species. ”

“ On the summit of Long's Peak, nearly three miles up, in a number of places I have seen bright primroses and polemonium, blue mertensia and lavender-colored phlox. There are ragged wild gardens of alpine flowers nearly thirteen thousand feet above the sea. More than one hundred varieties of flowers brighten the ledges of the cliffs, [Pg 182] fringe the snow-piles, and color the moorlands of the heights above the limits of tree growth. The alpine blooms that live in dry or wind-swept places are dwarfed and flattened. They keep their beauty close to the earth. ”

“ Stretching onward and upward to the line of the eternal snow, there are encountered the Cryptogamia—the lichens and mosses of Alpine growth—just as they are found within the limits of the polar circle; so that the traveller, who passes from the plains of India towards the high ridges of the Himalayas, or who climbs out of one of the deeper valleys up to some snow-clad summit that surmounts it, may experience within a journey of a few hours’ duration every degree of climate, and observe a representative of every species of vegetation known upon the face of the earth! ”

“ Yet, like the Arctic plants, they have rich, deep, and brilliant colours.
A queer point is that they have got so accustomed to this stormy and perilous existence that it is extremely difficult to grow them in a garden. Like mountaineers, they dwindle and pine away in the richer soil and softer air of the low grounds.
To make an Alpine garden, rocks and stones must be arranged with pockets and hollows, like natural crevices and basins, between them. Rich leaf-mould must be placed in these hollows. There must be good drainage, and as much sunlight as one can possibly get. ”