Chapter XXI: Appendix: I

NOTES ON PLANTS COLLECTED IN THE FAROES AND ICELAND

BY A. W. HILL, M.A.

The decumbent character of the vegetation and the practical absence of trees form the most striking features of the flora in both the Faroes and Iceland. In the Faroes the steep and rocky hillsides are very exposed and wind swept, and the vegetation is in consequence characteristically dwarfed, and most plants raise themselves but little above the general level of the grass.

The dwarfed habit was well shown by some plants, such as _Orchis maculata_, which was very common on the slopes, and was only a few inches high. The inflorescences did not, as a rule, bear more than five to ten flowers, which, however, were large and pale in colour. The ovaries in many cases were not twisted, so that the labellum was consequently uppermost.

Another example of the effect of the conditions on the vegetation was afforded by the dandelion _Taraxacum deus leonis_, which exhibited the prostrate habit exceedingly well, for in order to protect the flowers from the wind, the flower scapes were bent over and laid parallel to the surface of the ground and the inflorescence was exposed to the light by a right-angled bend of the scape just below the head of the flowers. The inflorescence was by this means protected from the wind by being kept just below the general level of the vegetation.

_Cardamine pratensis_ was also influenced in a similar way on the lower slopes, but at higher altitudes plants were found bearing single radical flowers on short stalks instead of the usual raceme.

We proceeded to Akureyri in the north of Iceland by way of the east coast, and it was interesting to notice the difference in the condition of the vegetation on the northern and eastern shores of the island. On the east coast, at Seythis-and Vopnafjords, the plants were stunted and for the most part only in bud; but in the north, at Husavik and Akureyri, similar plants were much earlier, and were not only in full flower, but were also much less stunted, and showed a more robust growth than those found on the eastern side. For example, _Plantanthera hyperborea_, which was in tight bud on the east coast, and also _Thymus_ and other plants, were in full flower at Husavik.

_Thalictrum alpinum_, which grows abundantly all over the hillsides, was found to be attacked by the æcidial stage of one of the rust fungi, _Puccinia septentrionalis_;[1] and at Seythisfjord, where it was especially noticed, it was found that only the topmost leaflets were affected, that is to say, only those leaflets which protruded above the general level of the vegetation, and which were in consequence infected by wind-blown spores. At Seythisfjord the leaflets were only slightly attacked, the fungus being in a young state; but at Husavik it was much more advanced, and the hypertrophied purple tissues were very conspicuous. The effect often extended some way down the petioles.

The case of the fungus is a further example of the greater forwardness of the plants in the north.

There can be no doubt that the characteristics of the east coast vegetation are due to the prevalence of cold winds and the occurrence of cold currents.

Whilst crossing the island several interesting features of the vegetation were noticed. Between Akureyri and our first camp (Thverá) several "forests" were passed through, consisting of _Betula nana_, _Vaccinium uliginosum_, and Willows, _Salix lanata_ and _S. glauca_ rising to a height of from nine to eighteen inches, with an undergrowth of other small plants.

The hillsides all round were covered by _Dryas octopetala_, which was by far the commonest plant in the northern half of the island, and it was abundant also on the east coast.

Travelling along the Oxnadal and then turning off towards Silfrastathir, _Dryas_ at first was the most conspicuous feature of the vegetation covering the rocky moraines and talus slopes; but about three miles from the head of the valley the _Dryas_ was replaced by _Cerastium alpinum_ and _Potentilla maculata_, which then in their turn became the dominant plants for a considerable distance. As we traversed the island we kept passing through well-marked zones of different plants, whose limits seemed largely to be determined by the character of the soil.

After crossing the "col" some very rough screes were passed, on which the Iceland poppy, _P. nudicaule_, was growing abundantly. The screes were formed of rough angular blocks with very little soil between them, and the poppy was only growing in the most barren spots; where moraines occurred the poppy did not grow. It was also found on the stony ground by the river at Silfrastathir.

The hillsides were covered in many places by large tracts of _Equisetum_ (_E. arvense_ and _E. pratense_). The various species of the Equisetaceæ seem to be among some of the commonest plants of the island. The swampy regions by the rivers are covered with _Equisetum_ and _Scirpus cæspitosus_; and they are very abundant on the mountains.

From the river until we reached Gilhagi, the flora showed no features of any particular note; but a meadow there with large plants of _Saxifraga cernua_ in full flower was a very beautiful sight.

On ascending from Gilhagi a change in the flora was gradually seen. After about 2000 feet _Pedicularis flammea_ appeared and became common; on the lower slopes the leaves were green and the plants tall, but at greater elevations the plants became short and stunted, with deep red leaves. The high ground was very much broken up, being of a deep hummocky character and covered by a dwarfed growth of Willows, _Empetrum_, Mosses, etc.

Passing over ground from which the snow had just melted, the willows were found to be either still quite bare or just coming out into leaf, but everywhere in such barren places cones of _Equisetum_ were seen sticking up on pale brown stalks some six inches above the soil; the sterile green shoots do not grow up until some time after the appearance of the cones.

All around Athalmansvatn the ground was very hummocky, the mounds being from a foot to eighteen inches high, with narrow depressions or ruts between. The elevation of this region was about 2500 feet, and as the snow had only recently melted, everything was in consequence backward, _Thalictrum_ and willows, etc., not yet being in flower.

Leaving Athalmansvatn a large tract of hummocky ground was crossed, covered chiefly by _Cassiope hypnoides_, _Empetrum_, Willows, _Salix lanata_ and _S. herbacea_, Grey Lichens, such as _Cladonia_, and Mosses. After this our route lay across a piece of the northern desert land or _Sandr_, which is a barren, sandy, and stony expanse. The soil was a light brownish loam, and was easily blown about by the wind, and scattered all over it were large angular or rounded blocks of stone. _Arabis petræa_ was the only plant occurring in any quantity over this region, and it formed a very conspicuous feature in the landscape, growing in rosettes closely adpressed to the soil with the racemes of flowers growing out horizontally.

As we travelled on in a southerly direction, _Silene acaulis_ appeared and then a little thrift, _Armeria sibirica_, and the _Arabis_ became less frequent. Here the soil was more sandy, and the strong wind blew clouds of dust. Still farther south, _Armeria_ reigned supreme over the desert; but occasional patches containing _Silene acaulis_, _Potentilla_, _Cerastium alpinum_, and _Silene maritima_ occurred. Where the soil became more loamy, _Arabis petræa_ again came in. At the edge of the desert the willows were seen encroaching on the sand, and soon a willow and birch (_Betula nana_) scrub was passed through, which in its turn gave place to moister land with _Empetrum_, _Pedicularis flammea_, etc.

Near Blandá, _Salir phyllicifolia_ was noticed for the first time. A good deal of hummocky ground was also passed over, and its characteristic and invariable features were noticed (_v_. later).

After passing over very rough morainic ground with snow still lying in patches and quite devoid of vegetation, we reached Hveravellir, a perfect oasis in the desert. The hot springs and fumaroles occur along a long line of fissure, and warm up the soil of a considerable tract of country in their neighbourhood. The effect on the vegetation is most striking, for a strip of verdant meadow-land occurs in the middle of bare country, covered in many places with snow at the end of June. All the flowers occurring there were in a very forward state, and a large number of different plants were obtained; some spots were yellow with buttercups, and the ground was carpeted with thyme in full bloom.

_Botrychium lunaria_ occurred in quantity, and a very small variety of _Ophioglossum vulgatum_, _O. vulgatum_, var. _polyphyllum_, was found in a warm place. _Selaginella spinosa_ was also abundant.

On the edges of this warm tract barren land occurred and in many places snow, so that there was a very sharp contrast between the warm and cold earth; and on the latter the willows were only just coming into leaf. This tract of country occurs at the edge of the great lava flow from Strytur.

Towards Strytur the lava was in places covered by "hummocky ground," which showed the usual features noticed elsewhere.

The characteristic plants seem invariably to be:--

*_Carex vulgaris_ (_rigida_), a creeping variety.
*_Salix lanata._
*_Salix herbacea._
*_Cassiope hypnoides._
*_Empetrum nigrum_ (very abundant).
*_Vaccinium uliginosum._
_Loiseleuria procumbens._
_Armeria sibirica._
_Silene acaulis_ (not very frequent).
_Bartsia alpina._
_Pedicularis flammea._
*Two or three Lichens, species of _Cladonia_, and a Moss, _Rhacomitrium
lanuginosum_.

Those marked with an asterisk appear to be invariably present, the others are not so constant, but some are usually found.

Shortly after leaving Hveravellir the watershed of the island was crossed, and a marked difference in the flora was noticed in the valley, Thjofadal, on the southern side of the ridge, owing no doubt to the much greater rainfall which occurs on this, the south-western, side of the island.

Among plants noticed in this region, which had not been met with before, were:--

_Draba alpina._
_Cardamine bellidifolia_, and
_Ranunculus pygmæus_ (which grew upright in the valley, but was
prostrate and creeping on the surrounding hillsides).

Fungoid diseases were very prevalent in the valley, and _Saxifraga cæspilosa_, which was extremely dwarfed on the high ridges, was in many places badly attacked by a rust fungus.

_Saxifraga cernua_ was also affected by the conditions in this region, for in other localities north of the watershed all the plants were found with the usual terminal flower, but here no terminal flower was developed, and the upright stems bore leaves and bulbils only.

_Epilobium latifolium_ occurred among the stones in the glacier streams, and a very decumbent form of _Epilobium alpinum_ was common on the hillsides.

The hills all round were formed of loose morainic matter, the slopes consisting of fine sandy earth with pebbles, and the vegetation is distributed on the hillsides in the form of banks and terraces, thus giving the hills a peculiar appearance with very gentle steps. In some cases the vegetation has spread and grown over the edges of the terraces, and by further growth hummocks have been formed.

The formation of hummocky ground on a morainic hillside appears to be somewhat as follows:--

If conditions, such as snow-line, wind, etc. (on a bare hillside of sandy and stony ground) permit, isolated plants begin to appear, and collect soil around them by their prostrate habit of growth and with their roots; in consequence of the loose nature of the soil, and owing to the action of snow or water, slipping frequently takes place, and the plants tend to keep up the earth. As the plants spread, terraces get formed and the plants bank up the loose earth, and the mountain-side is then broken up into broad steps. The vegetation continues to grow over the edges of the terraces, and in consequence more soil is collected by the plants, and small mounds result, and later on, if the slope is not too great, true hummocks may be formed. If the slope is steep, the hummocks are usually flat-topped, but this is also often due to snow, wind, etc.

The hummocky ground usually seen occurs in fairly level country, and its origin may probably have been somewhat different from that just described; the hummocks are from one to two feet high, and the ruts between are often so narrow that two hummocks have frequently united. The normal breadth of a hummock is from one to two feet across, and it is closely covered by _Empetrum_ or _Cassiope_, with _Carex vulgaris_, the Moss _Rhacomitrium lanuginosum_, and the other plants already enumerated.

Hummocky ground was also met with in meadows at Gilhagi (near Maelifell); here they were covered by grass and other meadow-plants, and _Saxifraga cernua_ grew in masses in the depressions. These hummocks were on a hillside, and may have been originally formed in the manner already described; but owing to some change in the snow-line, meadow-land plants may have wandered up the hillside, and ousted the characteristic plants of the hummocks.

Our journey from Thjofadal to Gránanes lay for the most part over the lava-flows from Strytur, which were covered by a close-growing vegetation, large tussocks of moss, very dwarf _Saxifrages, S. cæspitosa_, _Empetrum_, _Salix herbacea_, and other plants usually found on the hummocks. True hummocks were, however, rare.

Near our camp and before the Svatá was reached we came to the end of the lava and crossed a sandy tract, and the usual change in the flora was at once noticeable; large clumps of willows bound the sand together, around which the soil collected, forming mounds, and patches of _Armeria_, _Arabia petræa_, _Silene_, and _Arenaria_ were scattered about. In some places the willows were killed by having been buried in the blown sand.

Between Gránanes and Hvitarvatn the country is at first hummocky, and then covered by birch and willow scrub. On the hummocks, especially in the patches of moss, _Saxifraga Hirculus_ was not uncommon. The large tract of swampy ground at the edge of the lake was covered by masses of cotton grass. Leaving Hvitarvatn our way lay through willow scrub until the Hvitá was reached. After crossing the river the ground was very rough, being composed of morainic matter from the adjacent mountains and covered with large angular blocks of lava. The only flowers growing here were _Arenuria_, _Armeria_, _Thymus_ and _Dryas_ in isolated patches. As we travelled farther south, the plants were noticed to be taller and more vigorous than those seen in the interior, and the flora was more home-like in character. _Juniperus_, _Betula odorata_, _Calluna_, and _Arctostaphylos uva ursi_ were noticed for the first time.

Both birches (_B. odorata_, _B. nana_) were very plentiful, and from two to three feet high (in the north _B. nana_ was only six to nine inches high) willows were not common.

Between Sandá and Gullfoss another small desert area was traversed where earth-pillars occurred. The plants were hardly able to exist, as the smaller ones were blown away, and the willows and birches were in many places buried by the blown sand.

Around Gullfoss the vegetation was luxuriant, _Geum rivale_, _Geranium sylvaticum_, and _Alchemilla vulgaris_ covered the ground, and above _Rubus saxatilis_ and _Frugaria vesca_ were abundant, whilst _Arctostaphylos uva ursi_ also grew in profusion.

At Bratholt we reached civilisation again, and were presented with some of the lichen from which the orange dye, still used in the island, is obtained.

Between Geysir and Thingvellir we passed through one of the largest forests in the island; the hillsides were covered with birch-bushes, and in places they were quite six feet high; usually they did not rise to a height of more than three or four feet, and the topmost branches became entangled in our legs as we rode among the bushes. All four species of birch were noticed, and the scent of the bruised leaves was very pleasant. By way of undergrowth, the ground was carpeted with _Geranium sylvaticum_, _Ranunculus repens_, and large patches of _Orchis maculata_, etc. It was altogether a beautiful spot, and we spent nearly four hours wending our way through it. The river Bruará runs through the middle of this forest.

At Thingvellir _Gentiana nivalis_ was found among other plants.

The rarity of blue flowers in the part of the island visited by us, and indeed throughout the island, was very striking, as the only other blue flowers noticed, besides the gentian, were the _Veronicas_, and the _Myosotis_ and _Viola tricolor_ found at Akureyri, and _Campanula rotundifolia_ and _Pleurogyne rotata_, which were found on the east coast on the return journey. _Gentiana campestris_ and _G. nivalis_ were also found on the west coast. _White_, _pale pink_, and _yellow_ were the common colours, white being the predominant. The three most common orchids, _Habenaria albida_, _Habenaria viridis_, and _Plantanthera hyperborea_ were green and fairly inconspicuous. Perhaps the most striking flowers are the large rose-coloured _Epilobium latifolium_, which grows on bare islands of stones and black sand in the glacier streams, the yellow _Saxifraga Hirculus_, and _Dryas octopetala_, which covers vast tracts of country.

Between Thingvellir and Keykjavik is an extensive _Heithi_, over which we rode rapidly. There appeared to be no features of any special interest, and as the day was very wet it was not possible to study the flora carefully. On the beach at Reykjavik _Mertensia maritima_ is a fairly common plant.

The hot springs at Hveravellir and other places contain large quantities of algæ, mostly belonging to the blue-green family or _Cyanophyceæ_. Specimens were collected from various springs at Hveravellir, Kerlingarfjöll, and Geysir, and the temperature of the water in which they were growing was carefully recorded. As I was unable to examine them in detail, I sent them to Professor West of Cirencester, who has worked through my material and published a paper on hot-spring algæ in the _Journal of Botany_,[2] in which he gives a list of all the algæ we brought back from Iceland.

The highest temperature at which algæ were found was 85° C. (185° F.). Most of the forms found had not been previously recorded from Iceland, and there was one new species belonging to the genus _Aulosira_, _A. thermalis_. Full details of these interesting algæ will be found in the paper to which a reference has been given.