Part 2

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.

SUMMER FLOWERS OF THE HIGH ALPS

HERE FOLLOW COLOURED PLATES AND DESCRIPTIONS OF 39 SWISS PLANTS, WITH THEIR NAMES IN LATIN, ENGLISH, FRENCH, AND GERMAN

The Narcissus-Flowered Anemone

(_ANEMONE NARCISSIFLORA_)

Many varieties of Anemone are found in Switzerland. Not only have we the common English Wood Anemone (_A. nemorosa_) of the early spring, and the much rarer Pasque Flower (_A. Pulsatilla_) of our downs, but there is also the white or yellow Alpine Anemone (_A. alpina_), which forms so marked a feature of the Alpine pastures in early summer. Even in July and August, when most of the flowers have faded, the feathery tufts of seeds of the Alpine Anemone are still to be seen as the so-called “Chamois’ beards.”

The Narcissus-flowered Anemone, here photographed, is a widely distributed plant. It occurs on grassy slopes and in pastures between 4000 and 7000 feet above the sea level, and seems to prefer a limestone soil. The finely divided leaves are well seen in the photograph. Unlike every other species of Anemone found in Switzerland the flower stalk bears not a single flower only but two to eight, or even more, and at the point where the flower stalk divides a green collaret or involucre is seen. The flowers are pure white inside, and their external surfaces are often slightly woolly and tinged with pink, especially in the bud. The seeds have no feathery appendages like those of the Alpine Anemone. The flowers are without honey. They are visited by pollen-collecting insects, and should these fail will become self-fertilised. The plant blooms in May and June, and some flowers may still be found even in July in the highest Alpine pastures. It is met with widely distributed over Central Europe, North America and Northern Asia, but is absent in Scandinavia. On account of the numerous closely allied species which are found in Northern Asia, it is thought that this plant may have originated in that region and then spread east and west to America and Europe respectively.

The Globe Flower

(_TROLLIUS EUROPÆUS_)

THIS large and stately plant is common in mountain pastures from the lower levels right up to 7000 feet. It has finely divided leaves and bright yellow globe-like flowers, borne on long stalks which are usually unbranched. It is evidently a near relation of the buttercups, but differs from them in the possession of numerous brightly-coloured sepals, which enclose and conceal the much smaller tongue-shaped petals. Although not exclusively Alpine, being found all over Central Europe, in Scandinavia, and the north of England, it has been included in this series because it is sure to be noticed by anyone visiting Switzerland for the first time.

It flowers in May, June, and July, and flourishes best in damp places. A much smaller form, bearing only a single flower, is found exclusively on high mountains (_var. humilis_). It should probably be regarded merely as a variety and not as a distinct species.

The Globe Flower, the Anemones, and the two species of Aconitum illustrated in the two following plates are all examples of the buttercup order, the Ranunculaceæ. The common yellow buttercup so abundantly found in Alpine meadows is _Ranunculus montanus_. This species very closely resembles the ordinary upright buttercup of our English fields (_Ranunculus acris_), which it replaces in the Alps, but differs from it in the possession of a solid (not hollow) stem and a hairy disc beneath the seeds. It is a somewhat smaller plant, with less numerous—generally only two or three—flowers.

The Common Monk’s-Hood

(_ACONITUM NAPELLUS_)

Several species of Aconitum are met with in Switzerland. They have all bright-coloured flowers, especially adapted for fertilisation by humble-bees. It is only where there are humble-bees to convey the pollen from flower to flower that seeds can mature, so that where these insects do not exist the Aconites cannot spread. The five sepals of the Aconite flowers are coloured for attractive purposes, the highest being especially large and helmet-shaped. Protected by this are the representatives of the petals, so modified and reduced that they no longer have any attractive function, and are only of use to the plant by producing honey. They form a couple of nectaries on long stalks inside the helmet-shaped sepal.

The Common Monk’s-Hood is found in rich moist meadows between 3000 and 7000 feet. It seems to be especially common in the neighbourhood of Alpine dairies and cow houses. It flowers in June and July, and is very poisonous. From the conical root, resembling that of horseradish, the preparations of aconite used in medicine are prepared. When applied externally, aconite causes tingling and numbness and may relieve the pain of neuralgia. Internally, it depresses the action of the heart and lowers the temperature of the body. Homeopathists still use it for this purpose, but in doses so small as to have no appreciable action whatever. The single straight flower stalk, closely packed with blossoms, is rarely branched in its upper part, though small branches may be met with below.

The Panicled Monk’s-hood (_Ac. paniculatum_) resembles the above rather closely, but differs from it in the more open arrangement of the flowers on the hairy flower stalk, which is usually branched near the top. The leaves of both plants are finely divided, but the sub-divisions of those of the common Monk’s-hood are longer and narrower, more strap-shaped in fact, than those of the panicled form.

The Yellow Wolf’s-Bane

(_ACONITUM LYCOCTONUM_)

This plant is a species of Aconite, and a close relation of the common Monk’s-hood illustrated on the previous page. It is common on the borders of woods and in bushy places between 3000 and 7000 feet above the sea level. In this species, which, like the common Monk’s-hood, is visited almost exclusively by humble-bees, the upper helmet-like sepal which conceals the honey is especially long. It is interesting to note that the humble-bees do not, in all cases, obtain the honey in the way intended by the plant. A dark spot is often to be seen near the tip of the helmet where a humble-bee has nibbled through the flower leaf and obtained access to the nectary direct. In this way the designs of the plant for cross fertilisation may be frustrated, for where the honey is obtained in this manner no pollen is carried from flower to flower by the insect visitor. _Aconitum Anthora_, which is rather like the above, has more finely divided leaves and darker yellow flowers which are much less elongated than those of the Wolf’s-bane. The flowers, in fact, closely resemble those of the common Monk’s-hood except that they are yellow instead of blue. Both plants are poisonous.

The Two-Flowered Violet

(_VIOLA BIFLORA_)

This pretty little plant is common in moist shady places between 3000 and 7000 feet all over Switzerland. It is also found in Bohemia, Silesia, the Vosges, and other parts of Central Europe. It flowers from May to August in the clefts of rocks, and amongst the boulders on the banks of streams. It was in just such a place as this that the present photograph was taken. The flowers are bright yellow, streaked with brown, and the dark green leaves are kidney-shaped and entire. Although there are several other violets with yellow flowers to be found in Switzerland, no other species has broad kidney-shaped leaves. The smooth, erect flower stalk, which also bears some leaves, frequently divides into two near the middle, each branch being terminated by a bright yellow flower. This character, which has given to the violet its name, is, however, by no means constant, and flower stems bearing a single or three or more flowers are also often seen. The number of flowers borne by the plant would seem rather to be determined by its size and vigour, which, of course, again depend largely on the conditions under which it grows.

The Long-Spurred Pansy

(_VIOLA CALCARATA_)

The Long-Spurred Pansy flowers in June and July, and is a typical Alpine plant. The high mountain pastures are sometimes literally carpeted with its large purple flowers, all turned towards the sun. It is common on sunny slopes and among rocky débris between 5000 and 9000 feet, and prefers a limestone soil. The underground stem of the plant bears at its extremity a small rosette of leaves, and a short flower stalk terminated by the single large flower. The flower, which has a delicate and sweet scent, is usually of a rich purple colour, much more rarely yellow (_var. flava_). Sometimes the purple becomes paler and a lavender variety results, and, rarest of all, the flower may be pure white. From the many other violets and pansies which are found in Switzerland, the species we are now considering is recognised by its narrow, notched leaves, by the upward direction of the lateral petals, and especially by the long, narrow spur, which is quite as long as the corolla.

Unlike most of the violets which are fertilised by bees, the Long-Spurred Pansy depends entirely on butterflies for the conveyance of its pollen. The narrow opening to the flower and the long spur, at the bottom of which the honey is concealed, are only suited to insects such as butterflies and moths with relatively long tongues. It is pretty to see the butterflies flitting from flower to flower, and Müller observed a single insect visit no less than one hundred and ninety-four different blossoms in 6¾ minutes.

The Box-Leaved Milkwort

(_POLYGALA CHAMÆBUXUS_)

The Box-leaved Milkwort is a shrubby mountain plant with a woody branching stem and leathery evergreen leaves, which resemble those of the common box but are somewhat thicker. The flowers occur singly or in pairs in the axils of the upper leaves. They consist of a boat-shaped corolla of a pale yellow colour, which becomes darker towards the tip, and two wing-like appendages, which look like petals but are really sepals. These are usually white but are sometimes purple red. It is stated that their colour is determined by the soil on which the plant grows and is white or pure slate; on calcareous, slate coloured.

The Box-leaved Milkwort is widely distributed in Switzerland, Germany, and Austria, between 1500 and 7000 feet, and grows on wooded hills and in dry rocky places, where it is often extremely abundant. It flowers from May till the end of August. The plant is quite distinctive and will be readily recognised. Although belonging to the Milkwort tribe it is quite different from all other species, which have red, white or blue, never yellow, flowers and deciduous, not evergreen, leaves.

The Common Milkwort (_Polygala vulgaris_) of our English downs and heaths is also found in the Alps. It is a small herbaceous plant with a slender stem, perhaps three or four inches long, which is thickly covered with leaves, and terminates in a cluster of pink, blue, or white flowers. _Polygala calcarea_, a nearly-related species found only in limestone districts, has sky-blue flowers and leaves for the most part clustered in the form of a rosette at the base of the stem.

The Creeping Gypsophila

(_GYPSOPHILA REPENS_)