This section is from the book "Sub-Alpine Plants Or Flowers Of The Swiss Woods And Meadows", by H. Stuart Thompson. Also available from Amazon: Sub-Alpine Plants: Or, Flowers of the Swiss Woods and Meadows.
Owing to the moisture of our climate and the mildness of our winters, we have various Lusitanian species, characteristic of Portugal and the south-west of Europe, which extend their range much further north in these islands, especially in Cornwall, Devon, Dorset, and the south-west of Ireland, than they do elsewhere. Among them are several Heaths, such as Erica vagans (it is found in very few places in Switzerland), Erica ciliaris, and the Conne-mara Heath (Dabeocia cantabrica). The common Bell Heather (E. cinerea) is not found at all in Switzerland, and in only one place in Germany, above Bonn; nor is Erica tetralix found in Switzerland. In fact, with the rare exception of E. vagans, Erica carnea, and Calluna (Ling) are the only Heaths in Switzerland.
Other western species found in England and Ireland, but not in Switzerland, are the little Butterwort (Pinguicula lusitanica), the tiny yellow Cicendia filiformis, Cotyledon umbilicus with its peltate, fleshy leaves, and Iris foetidissima, whose capsules, with bright orange-vermilion seeds adorn many of our Lias woods in autumn. We have also quite a number of bog or aquatic plants which do not occur in Switzerland. They include the Ivy-leaved Campanula, (Wahlenbergia hederacea), the Bog Pimpernel (Anagallis tenella), the Marsh St. John's-wort (Hypericum elodes) and the Bog Myrtle (Myrica gale). The Bog Myrtle is distinctly an Arctic and Western European species, and so isthe Bog Asphodel (Narthecium ossi-fragum). Neither of the two British Lobelias (L. urens and L. Dortmanna) is found in Switzerland. The former is purely Western European in its distribution, and the latter is more northern.
To sum up the chief differences between the Swiss lowland vegetation and that of great Britain or Ireland: in Switzerland there are no hills or commons covered with Bell Heather and Erica tetralix; no wet, sandy moors, such as those in Dorset, made picturesque with the same two heaths mingled with the beautiful Erica ciliaris and Bog Myrtle, the brilliant yellow spikes of Bog Asphodel turning coral-red in September, the little yellow Cicendia, the pale Pinguicula lusitanica, and the curious Hypericum elodes. In Switzerland the Gorse (Ulex europceus) and the Broom (Saro-thamnus scoparius) are hardly even seen, the former being native only near San Bernardo in Tessin; on her banks and hillsides there are no Purple Foxgloves, but two less handsome yellow ones; and in her lowland woods and hedges the bright blue Scilla bifolia takes the place in spring of our wild Hyacinths.
Excluding sub-species and varieties, there are at least 2540 species of flowering plants and ferns in Switzerland; or perhaps six hundred more than in the British Isles, notwithstanding their long coastline and great variety of geological formation. And yet we have very much to be thankful for - we have Alpine and Arctic plants in the north, on some of the highest mountains further south, and in Ireland; we have, as already stated, quite a number of Lusitanian and Atlantic plants in the south-west of England and Ireland. Then there is a large Germanic element chiefly in the east of England; a most interesting maritime flora, with a few species from the Mediterranean; and many others which come under either the British, English, or Scottish type according to H. C. Watson's types of distribution. Indeed, there can be few countries in the world with so many interesting types of vegetation as the British Isles. Insular floras are almost without exception interesting, and that of our own Islands is of special interest, and furnishes some of the greatest surprises.
One of the Continental botanists who took part last year in the Phytogeographical excursion in the British Isles wrote1: "However much we have seen in different countries, we still found many peculiarities in the British vegetation which are not seen elsewhere, and many features which are as striking and interesting as any we have ever met with." Unlike most islands, however, and especially those of the Mediterranean, the British Isles can boast of extremely few endemic species.
The peculiarities of many high Alpine plants are not so noticeable in the sub-alpines. It will be remembered that most of the high pasture and rock plants are of small stature, often growing in tufts, mats, or cushions; with small leaves arranged in flat rosettes pressed against the ground. The roots are often very long, sometimes penetrating several feet into the ground so as to absorb all the moisture and nutriment possible, and also to prevent them from being blown away bodily by the high winds so frequent in the Alps. Many of them are prevented from being dried up through too rapid transpiration by developing a copious covering of hairs or woolly tomentum, as, e.g., in Hieracium villosum and in Edelweiss. Most conspicuous of all is the abundance of blossom and the brilliant colour of many of the Alpine flowers, particularly of the blues, reds, and purples.
1 The New Phytologist, January, 1912, p. 28.
Some of these characteristics are less noticeable in the plants of the mountain woods and meadows, for the simple reason that there is no great cause for their existence; for the climate is less severe and the winds less high. But, though it is supposed that the extreme brilliance of the light at high altitudes has a great effect upon the colouring of the flowers, yet in that particular, and especially in the abundance of blossom, many of the sub-alpines can well hold their own. The rapidity with which they blossom is another point in common. A large number of Alpine plants are specially constructed with a view to flowering at the earliest possible opportunity, just as are the Arctic species. The shortness of the summer is naturally the chief reason which has led to such peculiarities. After the flowering stage is more or less over, the seeds have to ripen. Time must then be allowed for their dispersal under suitable conditions, and finally for their getting a good start before they are embedded in the first snows of winter.