No one can visit Switzerland for the first time without being struck with the singular beauty of its wild flowers. In the early summer the whole country from the lowland meadows right up to the snowline is ablaze with beauty. Probably in no other part of the world are the forms of the flowers more pleasing and their colours more brilliant. Hence it is that almost everyone who visits the Alps, however little interest he may take in the wild flowers of his own home, desires to know something of the wonderful new forms that everywhere meet his gaze. Here the charm of novelty also comes in, for at least half the flowers met with in the Alps are absent from the plains, and many of the species that occur in both situations have, as we shall see later, acquired such different characters at high altitudes as to be with difficulty at first sight recognised. Those who would see Switzerland in all its beauty, and as far as its floral treasures are concerned, at its best, must visit it in early June before the hay is cut. Otherwise they will miss the glory of the unmown meadows, and although many of the spring flowers, like the Crocuses and Primulas (Plate 35), may still be found in small quantities at high altitudes even in July, the striking effect of the large masses of these flowers will be entirely wanting.
If we travel to Switzerland by the ordinary tourist route, across Germany or France, and then ascend the mountain peaks, we shall, in the first part of our journey, notice but few differences in the vegetation from that to which we are accustomed. The wild flowers of France and Germany are very like those of the South of England and, except that perhaps the yellow Fuller’s Thistle (Circium oloraceum) may be seen in damp places near the railway, very little of botanical interest will be observed until the customs are passed and Switzerland itself is reached. Even here the traveller may be for a time a little disappointed. The first unfamiliar plant to be noticed will very likely be the Red-berried Elder (Sambucus racemosa). A little later, in some shady wood, the tall feathery Spiræa (Spiræa Aruncus), or the beautiful little May-Lily (Maianthemum bifolium), may be seen. Or a glimpse of the white-flowered Rampion (Phyteuma spicatum) or the Alpine Honeysuckle (Lonicera alpigena), with its twin red berries, may be had in passing. But not until the mountains themselves are reached will the tourist discover that he has entered into an entirely new plant world.
The main factor which determines the character of the flora of any given region in the Alps is its altitude. But we must not forget that there are other things to be considered beside the absolute height above the sea level, and the local conditions of exposure to the sun and protection from the cold winds are quite important factors. Generally speaking, it may be said that the climate is a good deal milder on the southern slopes of the Alps than in the north. Olives can be grown in some of the lower mountain regions of the south, and with them are found many of the plants of Southern Europe and the Mediterranean region which are never seen in places of the same altitude on the northern slopes. It is exceedingly probable that most of the lower parts of the Alps were originally covered to a large extent by forest trees. The oak, ash, and beech still flourish in many parts, although much of the original forest has been removed long ago, and used for building purposes or as fuel, and large areas have been thus cleared for meadow and pasture land. In many districts the spruce and the pine appear to be usurping the place of the other forest trees mainly because the young plants are less eagerly devoured by browsing animals, especially the goats. Below 4000 feet on the northern slopes and 5000 feet or a little over on the south side of the Alps may be described as the region of forest trees, and above this level the ordinary deciduous trees become dwarfed and scarce. That this altitude corresponds fairly well with a transition to a colder climate is seen by the change in the character of the herbaceous plants also. For the next 2000 feet we have the subalpine region covered mainly by Coniferous trees. Here are vast forests, particularly of Spruce (Picea excelsa) and Silver Fir (Abies pectinata). The former is the familiar “Christmas tree,” which grows to a great height on the mountain sides, its lower branches festooned with grey lichens. Besides these trees the Larch (Larix Europæa) on primary rock, and the Scotch Fir (Pinus sylvestris) and the Arolla (Pinus Cembra) are also to be seen.
Above 6000 feet in the north and 7000 in the south the Conifers become dwarfed and stunted, and gradually disappear to give place to the alpine region. Sometimes as we look along a valley the line of transition is seen to be abrupt and straight, at other times irregular and undulating. Bushes of Alpenrose, Juniper, and Alpine Willow extend upward to the Alpine region, but larger trees are entirely absent. Here are found in profusion the greater number of the plants and flowers peculiar to the Alps. Many of the species may of course be found in sheltered or secluded spots at much lower levels, but here are to be seen in abundance the bright-coloured Saxifrages, Gentians, Anemones, and Pansies, which make the Alps their particular home. Here are the alps or upland pasture grounds of the Swiss, and here are situated the châlets or summer homes of Swiss herdsmen. In June or July, when the pasture is becoming scarce in the valleys and when all the snow is melted on the mountain slopes, the native farmer packs a large copper caldron and whatever else he may require for making cheese into his bullock waggon, and accompanied by his cattle, and often by his family as well, treks upward. The “alps” may be two or three days’ journey from his home, so that he must take with him all that he will probably require for his two or three months’ stay.
The Alpine region extends from the upper tree limit to the snowline, which may be taken as somewhere between 8000 and 9000 feet. Some of the most charming and brightly coloured of Alpine plants like Eritrichium nanum and the Cushion pinks (Plate 9) are to be found just below the snowline. Even above this level flowering plants may be met with, for even at the highest altitudes bare rock is to be found from which the snow has been blown by the wind or melted by the sun, or where the slope is too great for more than a very thin covering to remain lodged. The Glacier Crowfoot (Ranunculus glacialis), a pink-flowered buttercup, has for example been found within a short distance of the summit of the Finsteraarhorn, the highest peak in the Bernese Oberland.
Just over two thousand different species of flowering plants are to be found in Switzerland, and a little over half of these are exclusively Alpine. In contrasting the flowers of the Alps with those of our own country, it may be first of all well to consider what we have that Switzerland has not. Of course our seashore plants will be mainly absent, but strange to say a few species of Thrift are here and there found, and the yellow Horned Sea-poppy (Glaucium luteum) even grows in the neighbourhood of Lake Neuchâtel. We are so used to the bluebells of our woods, the purple heather of our heaths, and the yellow gorse of our commons, that we hardly realise how glorious they are. In Switzerland the gorse is very rare, the bluebells are not found at all, and the bell-heathers are absent though the ling is found everywhere. Even the purple foxglove is replaced by a yellow variety. These facts should be borne in mind, lest a too unfavourable comparison be made with our own rich flora.
But the flowers of the mountains are truly wonderful, and it is their abundance as well as their bright colours that make them so striking. At the same time, it must be remembered that though so numerous neither the flowers themselves nor the plants that bear them are really larger than their lowland relatives. Indeed, in spite of their bright conspicuous flowers, the plants that grow at the higher altitudes are generally stunted and dwarfed. Most of the peculiarities of Alpine plants, which we will now enumerate, are to be accounted for by the conditions under which they live. That this is really so is shown by the fact that “within the bounds of what must unquestionably be regarded as a single species, individuals change in character as we ascend to higher altitudes, the leaves become more hairy and more fleshy, and the flowers brighter and larger.” Even more direct evidence of this is to be obtained by cultivating Alpine plants at lower levels and lowland plants at high altitudes. Not a few of the plants of the mountains when grown in our gardens at home change in character very considerably. They tend to elongate so that their leaves are separated by longer intervals of stem, and their hairy characters very largely disappear. The Bearded Bell-flower (Plate 26) may lose its bearded character, and the familiar Edelweiss may, in some cases, develop smooth green leaves almost as hairless as those of an ordinary plant. Conversely, we have the observations of Professor Bonnier, who cultivated the plants of the lowlands at high altitudes in the Alps and Pyrenees. Where the plants were able to grow at all they became, in most cases, stunted and dwarfed. The Jerusalem Artichoke, for example, which forms a tall leafy stem like a sunflower in the plains, became a short stumpy plant with leaves arranged in a rosette at its base. Generally speaking, the plants developed a better marked underground stem, and thicker, darker green leaves than the same species grown under more ordinary conditions.
One of the principal characteristics of Alpine plants is the extensive development of the rootstock and underground stem. This is required to protect them against the strong winds, and to extract as large a supply of water and nourishment as possible from the frequently scanty soil. But there is another consideration of at any rate equal importance. During at least half of the year owing to the white coverlet of snow, all activity in the Alpine plant world ceases so that the production of flowers and seeds, indeed all the vital processes of the plants must be crowded into the few months when the ground is clear. Crocuses and Snowbells and other plants are found blooming at the very edge of the snow, therefore everything must be ready for immediate flower production directly the snow melts. For this to take place a reserve store of nourishment is essential, and accordingly Alpine plants are furnished with thick underground stems and fleshy roots where the food substances can be stored.
It is further interesting to note that the number of plants that go through their life cycle in a single year and then die off (annuals as they are called), is in the Alps comparatively small, for most of the plants persist from year to year. Kerner states that while only 44 per cent. of the plants on the Danube plains are perennials, there are as many as 96 per cent. in the Alps. That this has something to do with the conditions under which the plants grow is seen by the fact that the annual meadow-grass (Poa annua) becomes perennial in the Alps. Annuals persist through the winter season, only in the form of seed, so that a single wet summer such as the last (1909), by interfering with the ripening of the seeds, might threaten with extinction an entire species. Annuals have but little food stored up for a sudden outburst of activity on the approach of spring, nor can the tiny root of a budding seedling obtain from the soil all that is necessary for the rapid production of flowers and seeds. Moreover, as we shall see immediately, the production of seeds is in most plants very largely dependent on the presence of insect visitors, and without them either less fertile seeds or no seeds at all are in most cases formed. Insects are said to be less numerous in the Alps than in the plains, and thus the assumption of a perennial character makes the existence of the plant less dependent on external conditions.
Another point which has already been referred to is the low stature and stunted character of so many Alpine plants. Undoubtedly there are marked exceptions, such as the tall Gentians; but, generally speaking, it must be admitted that mountain plants are short stemmed and dwarfed, the vegetative part of the plant being often merely represented by a wreath of leaves. This is also very largely the result of the peculiar conditions of plant-life at high altitudes. The bright sunlight by day and intense cold at night have both a retarding effect on the growth of the stem. As regards light, the converse result is well seen in the long, lanky shoots of a potato growing in a dark cellar. But there is also another factor of some importance. The green leaves of plants are constantly giving out as watery vapour the fluid which has been absorbed by the roots. The decreased atmospheric pressure at high altitudes, the general dryness of the air, and the bright sunlight by day all unite to accelerate this process. During the day the ground is warmed even to a larger extent than the air, and thus the absorption of water by the roots is correspondingly hastened. During the night the intense radiation rapidly cools down the soil on which the plant grows, but the surrounding air is not cooled to anything like the same extent. The result is that the absorption of fluid by the roots is diminished in a much larger degree than the effusion of watery vapour from the leaves, and the plant is in imminent danger of being dried up. To this danger the plants of high altitudes respond in various ways. In the first place, their stunted character not only diminishes the area of leaf surface for the exhalation of watery vapour and protects them to some extent from strong winds, but it also places them in the lowest stratum of air which is most likely to assume the temperature of the soil. The felted, cushion-like habit (Plate 9) of so many Alpine plants, and the rosette-like arrangement of their leaves (Plate 19), are also of advantage to the plants by exposing less leaf surface directly to the air. The succulent leaves of plants like the house-leeks (Plates 18 and 19), and the hairy covering of the Cat’s-foot (Plate 23), Edelweiss, and others, seem also designed to counteract the tendency to too rapid desiccation, and the tough leathery character of many leaves (Plate 7), and the thickened cuticle of others (Plate 30), are clearly of like value. The relatively increased thickness of the leaves of many Alpine plants is also, no doubt, due to the intensity of the sunlight, for direct experiments have shown that increased illumination has this effect. Their usual dark green colour is thought to result from an excess of the green pigment by which plants are able to extract the carbon required for their growth from the air. The rarefaction of the air and shortness of the season of growth at high altitudes, as well as the low stature of most Alpine plants, make it essential that assimilation should take place as rapidly as possible when conditions are favourable for it.
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. The colours of the flowers are, however, undoubtedly deeper and more intense. If we examine specimens of the same kind of flower, for instance the Forget-me-not or Eyebright, that have been found growing at different altitudes, we shall be struck with the deeper tints of the flowers from the higher regions. That this character has something to do with the conditions of life in Alpine districts is shown by the disappointment that we sometimes feel at the diminished brilliancy of the flowers of Alpine plants when grown in our gardens at home. The flowers of the Alps are also, as a rule, of a more highly organised type than those of the plains, and corresponding with this increase in complexity is a relative increase in the number of pink and blue flowers, and a diminution in that of the yellow and white. Alpine plants, too, seem to produce more honey than do the corresponding plants in the plains; at any rate, the yield of honey from bee-hives is greater, and Bonnier has shown that the secretion of honey by flowers of the same kind increases with the altitude, and that in some cases there is a corresponding increase in the intensity of the scent of the flower.
While many of the characteristics of Alpine flowers are to be explained as a direct result of the conditions of life at high altitudes, it is probable that the process of natural selection has also had a good deal to do with their production. One of the principal objects of the life of a flowering plant is to produce seeds. It has been shown that, generally speaking, more numerous and healthier seeds are produced when the seed-producing apparatus of a flower is fertilised by pollen from the stamens of a flower of a different plant. Hence arrangements have to be made by plants for the conveyance of their pollen from flower to flower. This is sometimes effected by the wind, but much pollen is lost, so that this is manifestly a very wasteful method. Plants have therefore adopted the more economical plan of getting insect visitors to do this carrying business for them. The bright colours and sweet scents are to attract insects to the flower, and honey is provided for their entertainment there. It is generally believed that the total number of insect visitors in the Alps is less than in the plains, and therefore the competition for their services being more severe, greater attractions in the form of brighter coloured flowers and more abundant honey have to be provided for them. But, unfortunately, the direct observations of H. Müller do not confirm this view. There can be no question, however, that the relative proportion of the several varieties of insects in the Alps is very different from that in the plains. There are comparatively few flies, bees, and wasps, but numerous humble-bees, butterflies, and moths in the mountain regions. These insects have longer tongues and prefer to visit flowers of a more complicated structure, where the honey cannot be reached by their shorter tongued relatives. Flowers of this sort with less easily obtained honey are more often of a red or blue or pink colour, and more rarely of a yellow tint. Not a few Alpine flowers like the Aconites (Plates 3 and 4) are entirely dependent on humble-bees for their fertilisation, and an even larger number, such as the Long-Spurred Pansy (Plate 5), and several of the Gentians are exclusively visited by butterflies and moths. Müller even goes so far as to suggest that not a few of the Alpine flowers, especially those of a pale crimson colour and with a clove-like smell, such as the Pinks (Plate 9), have been evolved in the Alps under the influence of butterflies and moths. In spite of this it is curious to note that the number of flowers that are habitually self-fertilised is greater in the Alps than in the plains. But when it is explained that these are for the most part of the same type of flower that is pollinated by flies, bees, and wasps in lowland districts the apparent anomaly becomes clear.
The question of the origin of the Alpine flora is a subject upon which botanists are by no means completely agreed at the present time. A large number of the thousand different plants that are found in the high Alps reappear in distant mountains and the Arctic regions, though absent in the intervening country. Thus the late John Ball calculated that 17 per cent. of the Alpine species were met with in the Arctic regions, and 25 per cent. in the Altai Mountains of Northern Asia. That this is not due to the conveyance of seeds from place to place by the agency of wind or birds is shown by the fact that the resemblance of the plants of different mountain chains to one another is in no way proportional to their geographical proximity, even when their climate is similar. The true explanation is probably to be sought in the Glacial Period, in which the greater part of Europe was covered by ice, so that the climate of the plains was very similar to that of the high Alps and Arctic regions at the present time. At this period the flora of the extreme north was able to mingle with that of the mountain regions. 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. Either the flowers are pressed, or the plants are pulled up with more or less of their roots to be planted in some garden at home, or, as the author would suggest is by far the best method, photographs of the plants are taken. May we here, first of all, protest against the wholesale destruction of Alpine plants that goes on every year by careless visitors. Where a few flowers are required for study or to be preserved by pressing, they may, by all means, be picked. There seems no reason also why a few of the more common or abundant plants should not be dug up with their roots, carefully packed, and taken home, although the Swiss authorities do not permit even this, but it is disgraceful that large nosegays of choice flowers should be gathered for the mere pleasure of watching them wither in the hand, and then thrown away. The Swiss natives, unhappily, set us a very bad example in this respect; but it is fortunate that the Edelweiss and Alpenrose are the only flowers that they at all extensively attack. Many of the more frequented tourist routes have become almost bare of any but the commonest flowers. One has only to ascend to some peak or glacier by two paths, one that is well-trodden, and a second but little used, to see how complete this destruction of wild flowers has been.
Excellent little presses for preserving plants and flowers can be bought in Switzerland. They take up no more room in one’s bag than a Baedeker or Bradshaw’s Guide, and do the work much more efficiently. Their only disadvantage is that they are generally too small to display any but the tiniest plants completely, and it is really wiser to take out from England a couple of boards with straps and a good supply of blotting paper. The special paper sold for pressing plants is much to be preferred to ordinary white or pink blotting-paper, as the plants tend to stick to it much less. A fair amount will be required, as the plants need frequent changing and the paper must be dried. Specimens should be carefully set out by pressing on them with the finger till they take up the required positions, and stored when dry in some exercise book or between sheets of paper.
The cultivation of Alpine plants in our gardens at home is by no means as easy as might at first be supposed. The climate and conditions of life in Peckham are very different to those at the summit of Pilatus, and unless the thing is done carefully and thoroughly it had better not be attempted at all. The chief difficulty in growing Alpine plants in our climate is not the cold but the excessive moisture of winter, which tends to rot their roots, and from which they are protected in their native home by their snowy covering. Our object should be to reproduce, as far as possible, in our gardens the conditions under which the plants grow in the high Alps. For the rockery a porous stone will be required, such as limestone or sandstone, and it is essential to select a kind that does not crumble with the frost. The partially fused masses of brick, which can be obtained very cheaply as a waste product from brick kilns, when washed over with a mixture of cement and sand do very well. The rocks and stones must be so laid that every bed or pocket in which the plants are to grow is thoroughly well drained, for nothing is so destructive to them as water-logging of the soil. Plants that grow in the clefts of rocks should be planted in a sloping position, as water is then less liable to collect in the rosettes of leaves. Those that grow in cool, moist, spongy soil are best planted in a mixture of peat moss and earth. It is also important to notice whether the plant which is being cultivated was previously growing on limestone or granitic soil, for it is easy to add a little chalk to the earth if this is required. In planting out one has to be careful not to curl up the roots, and it is wise to sprinkle the plant with water two or three times a day for the first week or so. Alpine plants should never be manured. It should be remembered that mountain plants grow slowly, and though very many species can be successfully cultivated, the Houseleeks and Saxifrages are likely to give the best results with a minimum of trouble.
It is impossible in such a book as this to give more than a few general suggestions as to the photography of Alpine plants. One of the chief difficulties with which one has to contend is the wind. When the plant is photographed anywhere near its natural size the smallest stop has to be used to obtain depth of focus, and this greatly increases the duration of the exposure. Many of the colour photographs herein reproduced were given as long as five or ten minutes. When the wind is intermittent it is quite safe to give repeated exposures of a few seconds at a time, being careful in removing and replacing the cap not to shake the camera, for the plant is sure to return to exactly the same position after being blown to and fro by the wind. Where tall plants are being taken it is wisest to select a time in the early morning or near sunset, for though the intensity of light is diminished at these times, there is usually but little wind. The writer has found a strip of white calico, some 12 or 15 inches wide, with long knitting needles sewn on to it at intervals, of great value as a wind screen in plant photography. The knitting needles can be pushed into the ground, and the plant surrounded on three sides or completely by such a screen, and thus very largely shaded from the wind. With a little care the screen does not appear in the photograph, and it is easily rolled up and carried from place to place. For near objects the intensity of light in the Alps is only slightly greater than that in England at the same time of day, but it is always wiser to make use of an exposure meter if the best results are desired. By the use of the swing back any plane surface, whatever be its inclination to the vertical, can be easily focussed. This will be found of especial value where a blurred background is desired, and the slight distortion thus obtained, which is so noticeable in architectural subjects, is quite negligible in the case of plant portraits. The deep shadows that are produced when flowers are photographed in bright sunlight are generally best avoided.