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OTHER DWELLERS ON THE HIGHEST SUMMITS
We have almost completed our survey of the dwellers on
the highest summits and have described all the more important members of
the high alpine flora of the Highlands. We are left with a few plants,
rather less interesting perhaps than those we have already described, but
that is no reason why we should pass them over. All plants, even the most
humble, are worth studying and we shall find that the few remaining
species merit our attention.
They are the Rock Whitlow-grass (Draba rupestris),
one of the Cruciferous family found very rarely n the rock crevices of
some of our highest mountains; Dwarf Cudweed (Gnaphalium supine), a
very common alpine belonging to the great Composite family; Alpine
Forget-me-not (Myosotis alpestris), a very beautiful, but very rare
species and the only representative of its family in our mountain floral
Snow Gentian (Gentiana nivalis), the only Gentian to be found in
our mountains although other species occur in the Lowlands; four species
of Pearl-wort (Sagina); three species of Speedwell (Veronica);
and certain species of grasses, sedges and rushes.
Snow Gentian
(Gentidna nivalis)
The
mountain climber who finds this delightful and exquisite little plant can
think himself very luck for it is indeed very rare. As one might expect,
that mountain of rarities, Ben Lawers, is one of its stations, whilst the
only other spot where it ahs been found is in the wild, rock fastness at
the head of Glen Isle. Unfortunately, it is a decreasing species and the
day is probably not far off when we shall have to efface if from our flora
as an extinct species. Why it should be so rare is difficult to say for
it is a fairly common species in most of the European mountains. Probably
changing climatic conditions have a lot to do with it and it may have been
much more common in the past.
No one who has not seen the Snow Gentian in its natural
surroundings can even imagine how intensely blue the flowers really are.
I will not try to compare this tiny gentian with the beautiful Spring
Gentian of the Swiss Alps, and its many beautiful relatives that make the
Swiss meadows such a blaze of colour. Nevertheless, our little gentian,
although very rare, is an exquisite representative of its family.
We have read of the intense colouring of alpine flowers
and especially of the brilliant blues of the gentians, and some of us have
perhaps wondered, what can be the reason for this. This is a question
which has not yet been satisfactorily answered. It may be due to the
great intensity of sunlight in alpine situations or it may be a special
adaptation to aid cross-pollination by insect means. We know that, under
suitable conditions, intense illumination has the effect of making the
chlorophyll of leaves a much brighter green, and in the same way those
flowers whose pigments are in the form of granules in specialized cells as
is the chlorophyll in the leaves, may be affected. On the other hand,
most blue-flower colours are due to pigment dissolved in the sap, and are
unaffected by light intensity.
Again, many flowers are highly specialized for certain
insects and are colored so as to attract the particular insect needed to
effect cross pollination. Blue is the colour of flowers that are usually
highly specialized for pollination by bees and depend almost entirely on
these insects. The Snow Gentian, like all blue gentians, is in this
class. In the high regions, where it grows, insects are not very numerous
and it may be that in order to make sure of being visited, the gentians
have intensified the blue of their petals to make them much more
conspicuous. This seems the likely explanation.
The Snow Gentian is a very small plant, often only one
inch tall and seldom more than four. It is very peculiar among alpine
plants in being an annual, which probably accounts for the fact that it
does not flower till the end of the summer. The seeds must wait until the
snows have cleared in the late spring or even early summer before
germinating the plant must then produce roots, stems, leaves and flowers
before the end of August. It could hardly get through its life cycle more
quickly and so flowering is late. This also helps to account for the
smallness of the plant.
Each plant consists of a single, very slender stem
which is not branched in the smaller specimens, but may be branched once
or twice in the larger specimens. The stem and branches are clothed with
a few small, pointed, opposite leaves and are each terminated by a small
solitary flower.
The flower is shaped like a narrow bell, the petals
being united for three-quarters of their length. The upper free portion
is bent at right angles to the tube, so that from above the flower has the
appearance of a five-pointed star. The five stamens spring from the base
of the tube and their filaments are quite free from one another. Their
anthers, however, are united in to a ring which almost closes the entrance
to the tube. This anther ring embraces the lower part of the style,
whilst above it project the two stigmas. The nectaries are placed at the
base of the ovary, which is situated at the bottom of the bell. Only
cleared in the late spring and even early summer before germinating; the
plant must then produce roots, stems, leaves and flowers before the end of
August. It could hardly get through its life cycle more quickly and so
flowering is late. This also helps to account for the smallness of the
plant.
Each plant consists of a single, very slender stem
which is not branched in the smaller specimens, but may be branched once
or twice in the larger specimens. The stem and branches are clothed with
a few small, pointed, opposite leaves and are each terminated by a small
solitary flower.
The flower is shaped like a narrow bell, the petals
being united for three-quarters of their length. The upper free portion
is bent at right angles to the tube, so that from above the flower has the
appearance of a five-pointed star. The five stamens spring from the base
of the tube and their filaments are quite free from one another. Their
anthers, however, are united into a ring which almost closes the entrance
to the tube. This anther ring embraces the lower part of the style,
whilst above it project the two stigmas. The nectaries are placed at the
base of the ovary, which is situated at the bottom of the bell. Only an
insect such as a bee or butterfly with a long, fine tongue can reach this
nectar.
When a bee arrives upon a young flower, it pushes it
tongue down among the stamen filaments to reach the nectaries and receives
the pollen on its head and upper tongue. ON leaving it probably leaves a
little pollen on the stigma, but, as this is not receptive until all the
pollen is shed, self-fertilization does not take place. On going to an
older bloom in which the stamens have withered, the bee leaves some pollen
on the now receptive stigma and thus cross-pollination is ensured.
We have already spoken of the bright colouring of this
gentian, but to see it one must go on a sunny day. Whenever the sun is
coveted and there is danger of rain the flower closes by twisting its
petals into a spiral. So sensitive is this flower to change of light
intensity, that the passage of a cloud across the sun is the signal for it
to close. On a cloudy day it may thus open and shut many times. When the
flower is fertilized the bloom fades and a capsule containing many small,
light seeds if formed. It opens by valves and the seeds are jerked out,
often to a considerable distance, by the wind.
Rock Whitlow-grass
(Draba rupestris)
This
plant is a close relative of the Spring Whitlow-grass which is so common
in the Lowlands in early spring. It has a short tufted stem surmounted by
man y short, narrow leaves which are slightly toothed and are covered with
a few silky hairs. The stock sends up a short, fine flower-stalk which is
terminated by a few small, white flowers. They have, as in all crucifers,
six stamens, four of them being long and two short. The stigma matures
with the anthers and the long stamens shed their pollen on it, thus
self-fertilizing the bloom. The plant, however, does not depend
altogether on self-fertilized seeds and secretes nectar at the base of the
two short stamens. Bees visit the flowers for nectar and transfer some
pollen from the short stamens to the stigma of the next flower they
visit. Thus some cross-fertilization seed is set to save the plant from
degenerating.
This little plant is also very rare and must be
searched for with diligence. It can be found on several spots on Ben
Lawers, very rarely on Cairngorm, on Ben Dothaid in Argyllshire, not far
from Glen Orchy, and on Ben Hope in Sutherland. It is a member of the
Arctic flora and its Scottish stations mark its most southern limits.
Dwarf Cudweed
(Gnaphalium supine)
This
plant is very small, but as it forms large colonies it is quite a
conspicuous features of the dry rocks and the screes that it loves. It
has short stock covered with the withered leaves of other years; above
this are crowded many linear leaves which have a grayish hue. This is
caused by the dense covering of cottony hairs which hide the real green of
the leaf. Like many plants growing in very dry places it has developed
thick hairs to cover the stomata and cut down transpiration to the
minimum. Not only the leaves, but the flower stock and bracts all have
the same covering, so urgent is the need to conserved the water supply.
This plant has several close relatives in the Lowlands, all of them
possessing the same hairy coat. It is a humble relative of the Edelweiss
of the Swiss Alps in which the hairy coat has been taken to an extreme.
From among the leaves arises a short flower stalk
surmounted by four or five brownish heads of flowers. These are composed
of many small florets. This plant is a composite and its fertilization
will be dealt with in an ensuing chapter.
It is widely distributed, being found over a wide
degree of altitude. I have found it at 1,600 feet on the shores of Loch
Einich and at 4,000 feet on Cairngorm and Ben Nevis.
 Alpine Forget-me-not
(Myosotis alpestris)
This
is one of our most exquisite British plants and its heavenly blue flowers
remind one of southern skies or the azure waters of the Mediterranean.
Its blooms are much larger than those of the Forget-me-nots of the
Lowlands.
The short stock is crowned by several shortly stalked
leaves, which are covered with one, rough hairs on both surfaces. It
sends up a long flower-stalk which has several leaves upon it. It is also
roughly hairy and is surmounted by a small cyme of large, very bright,
blue flowers.
Each flower is tubular and has a bright yellow ring
around the entrance to the tube. This acts as a honey guide to insect
visitors. Each petal has a small scale on it, just below the ring. This
protects the anthers from rain. A bee, arriving on the bright blue
platform and pushing its tongue down between the anthers and stigma to
reach the nectarines, will leave some pollen on the stigma. Thus the
flower is pollinated. At the same time the bee’s tongue will touch the
anthers and thus fresh pollen will be taken to the next flower visited.
Failing insect aid the stamens shed their pollen on the stigma and
self-fertilize the blooms.
This lovely flower is unfortunately exceedingly rare in
our mountains, being confined to the summit of Ben Lawers. Strangely
enough it appears again on Mickle Fell in Teesdale and nowhere else in
Britain, although it is fairly common inmost of the European mountain
ranges.
ALPINE SPEEDWELLS
The Scottish Highlands possess three Alpine Speedwells,
two of them very rare plants and one very common and well distributed.
They are the Alpine Speedwell (Veronica alpina), the Rock Speedwell
(V. fruticans) and Veronica humifusa.
Alpine Speedwell
(Veronica alpina)
This
little alpine has a short creeping stock, which sends up weak, leafy
branches, which usually creep over the rocks where this plant is found.
They never branch, and are usually from two to five inches long and
slightly hairy. The leaves are oval and of a very deep green. At the
summit of the branch is a raceme of four or five rather small, very deep
blue flowers.
The flowers are pollinated by hover-flies. There are
only two stamens which are found to the left and to the right of the
pistil. In the young flowers the stamens are curved downwards so that the
anthers are held in the tube of the corolla. The stigma protrudes well in
front of the flower on a long curved style. As a hover-fly sucks the
nectar the under part of its body touches the stigma. In older flowers
the style bends down out of the way, and the two stamens take up their
positions in such a fashion that their anthers are in the position
originally held by the stigma. A hover-fly visiting such a flower will be
dusted with pollen underneath, just where the stigma of a younger flower
is sure to touch it.
If insects do not visit the flowers, the stigma remains
in position and will be pollinated by its own stamens when they take up
their position. Thus some seeds will always be set.
This plant is to be found along the sides of streams
and among damp rocks on most of the highest summits of the Cairngorms, the
Clova mountains, the Perthshire mountains and the Ben Nevis range.
Rock Speedwell
(Veronica fruticans)
This
speedwell has much the same habit as the Alpine Speedwell but the stock is
usually woody, while the branches and leaves are completely glabrous.
The flowers are rather large and of a very bright blue
with a white eye, which surrounds the entrance to the tube and forms a
honey guide. It is also pollinated by hover-flies.
It is found in drier situations than the preceding, but
only at very high altitudes on the mountains of Perthshire and more
abundantly in the Clova and Glen Isle area.
Veronica humifusa
This plant is a close relative of the
lowland Thyme-leaved Speedwell (V. serphyllifolia) and is well
distributed throughout the Highlands, occurring on most of the higher
mountains, especially on the damper rocks and slopes.
The plant sends out short, creeping stems which are
much branched and form dense leafy tufts, and this forms the perennial
portion of the plant. The flowering branches are erect and are from two
to five inches in height. They distinguish the plant from V.
serphyllifolia
as they are usually downy, whereas in that species the
whole plant is glabrous. They are clothed with alternate, stalkless,
ovate leaves which resemble those on the creeping stems, but are rather
smaller. They are quite smooth with a crenate border.
The flowers are produced singly on very short pedicels
in the axils of all the upper leaves. They are very small and of a pale
blue or white colour with darker violet veins which function as
honey-guides. Small bees and flies visit the flowers, but as they are so
inconspicuous their visits are irregular and self-fertilization often
takes place.
THE ALPINE PEARLWORTS
We have four Pearlworts which may be found in the
Scottish alpine regions. Three of them, Sagina saginoides, S. scotia
and S. nivalis, are typical alpine plants, but the fourth S.
procumbent, although common many of the highest mountains, is actually
a lowland plant. As it is much more likely to be found than the others
and is easily confused with them, it is better to deal with it here.
As the Procumbent Pearlwort is familiar to so many
people a long description might seem out of place, but its smallness makes
it a difficult plant to examine properly. It is a perennial plant only
one or two inches high. It has a very short main stem giving rise to many
spreading branches which give the plant a very tufted appearance. It
usually grows in crevices of rocks and among stones so that the stem is
hidden from view. The stock is usually crowned by a tuft of small,
awl-shaped leaves which appear glaborous, but are often covered with a
very short down. The stems are clothed by similar pairs of shorter laves
whose bases are joined by a tiny, membranaceous sheath. From the axils
of the upper leaves rise single, very slender pedicels which are
terminated by a solitary, very small flower.
The parts of the flower are in fours and this
distinguishes it from the other alpine species. The four green, narrow
sepals are only one-twelfth of an inch in length, whilst the minute, white
petals are still shorter or are often completely absent. Within are four
stamens with short filaments and very tiny, yellow anthers. The tiny
round ovary is terminated by four spreading styles.
The anthers and stigmas mature together and are so near
to each other that self-fertilization usually takes place. In spite of
the minute size of the flowers, tiny drops of nectar are secreted at the
bases of the sepals. This probably attracts very small insects as thrips,
aphides, ants and flies which are often found upon the plants. These may
occasionally cross-pollinate the flowers.
The next species S. saginoides (S. Linnaei)
is a much rarer plant and only to be found on rocky ledges and stony
debris near the summits of Ben Lawers, Ben More and other high Perthshire
and Argyll mountains, on most of the cairngorms, on the Ben Nevis and
towards sea-level in Sutherland.
It is very similar in habit to S. procumbent, but its
spreading branches often take root where they touch the soil and give rise
to new whorls of branches. Hence it forms low, dense, cushion-like tufts
which are very bright green in colour. The five petals are nearly as long
as the five sepals, whilst there are ten stamens and a five-styled ovary.
It is distinguished from S. nivalis by the fact that the pedicels
are curved during the flowering period, but becomes erect in fruit, whilst
in the latter the pedicels are always erect.
S.scotica
closely resembles the preceding and is
often confused with it, but its petals are larger than the sepals and the
plant is completely glabrous. It is confined to precipices and grassy alps
of the Perthshire and neighboring Argyll mountains, and also Clova.
The remaining species S. nivalis is one of the
rarest alpine plants and is only to be found near the summit of the Ben
Lawers and Am Biennien in Perthshire where is grows in rock fissures and
on stony debris. It is a very densely tufted little plant, very similar
to S. saginoides, but it has shorter petals and broader leaves.
Alsine rubella
This
tiny plant, a member of the Pink Family, is very rare in the Highlands,
being confined to certain spots on the summits of the Breadalbane Mts.,
and on Ben Hope in Sutherlandshire.
Its rootstock is usually buried under a loose piece of
rock, and its summit is covered by the old dead leaves. It gives rise to
short, creeping branches, covered with small, awl-shaped leaves of a
yellowish-green colour. Each plant produces sever, short, erect flowering
stems, which are often one-flowered, but may produce three or four. The
stalks are downy and thus protect the flowers against crawling insects.
The small, white flowers are inconspicuous and usually self-fertilized,
although small flies visit them and may sometimes cross-pollinate them.
It is a close relative of the Vernal Sandwort, which is
much more common in the Lower mountain pastures.
ALPINE GRASSES, SEDGES AND RUSHES
No description of the Scottish alpine plants would be
complete without some allusion to the numerous grasses, sedges, and rushes
which make up so large a part of our mountain vegetation.
The grasses are especially abundant and owe this to
their prolific yield of seed, their perennial habit and their production
of runners and offsets, by which the plants reproduce themselves and
colonize huge areas.
The underground stems, rich in stored food substances,
allow the plant to commence its growth as soon as the weather permits in
the spring. These stems branch and send off runners which root a the
nodes and produce daughter plants. One plant can thus colonize a large
area, whilst their close matted roots and their large tufts of leaves make
it difficult for other plants and seedlings on the frontier areas. Their
inconspicuous flowers, which are wind-pollinated and are thus independent
of insects, produce abundant seed and as the stigmas mature before the
stamens, cross-pollination is usually assured.
The grasses of the Scottish alps may be divided into
two classes. In one we have the real alpine grasses which are only to be
found in the higher pastures and do not descend far down the
mountain-sides. A typical species is the Alpine Fescue Grass (Festuca
alpina), which is actually an alpine variety of the very common
Sheep’s Fescue (F. ovina). It is a low, tufted, perennial grass
with almost cylindrical leaves whose stomata are enclosed in the cylinder,
and so excessive transpiration is checked. The flowering spikes which
only rise a few inches above the tuft of leaves do not often produce
flowers. Instead the spike lets form small leafy shoots which drop off to
from new plants. This is called vivipary and is explained by the short
flowering season.
Four members of the genus Poa are to be found in
the alpine pastures. The Alpine Meadow- grass (Poa alpina) is
another tufted grass in which the leaves are flat and the panicles
resemble those of the ubiquitous Annual Meadow-grass, but the spikelets
are as wide as they are long and are tinged with violet. They rarely
produce seed, but become viviparous and form leafy shoots. It is rather a
rare plant, but can be found on the higher mountains of Perthsire, the
Cairngorms, the Ben Nevis range and again in Rosshire. The Glaucous
Meadow-grass (P. glauca) is a rare plant confined to lofty
mountains such as Ben Lawers, the Clova mountains and Ben Nevis. It is a
slightly creeping plant with smooth, narrow, glaucous leaves of a
bluish-green colour. It has a very slender panicle of very small spike
lets which are also of bluish-green colour. Another species, Poa
Balfourii, is also very rare in the high mountains of Perthsire,
Angus, Inverness-shire and Argyll. It is very similar to the preceding,
but its leaves are not glaucous and the small spike lets are often covered
with tiny, cottony hairs. The remaining species, Wavy Meadow-grass (P.
laxa), is closely allied to the Alpine Meadow-grass, and although
found on Lochnagar and Ben Nevis, is very rarely discovered. It has
deeply channeled leaves, and its small spike of flowers is often webbed
with cottony hairs.
Two other rare grasses complete the list of our real
alpine grasses.One, the Alpine Cat’s-tail (Phleum alpinum), is to
be found on wet, rocky ledges and damp slopes on the higher mountains of
Perthshire, Angus, the Cairngorms and the Ben Nevis range. It is a
perennial of low stature and the solitary stem is terminated by a short,
dense spike of purplish spike lets, the glumes of which have very short,
bristle-like awns.
The other species, the Alpine Fox-tail (Alopecurus
alpines), is a very rare plant and confined to wet alpine slopes on
Braeriach, Ben Macdhui and Ben Nevis. It has an erect, leafy stem arising
from a creeping rhizome. The flower spike is short and dense and softly
silky because of the long hairs which cover the glumes.
The second class of grasses found in the alpine
pastures and usually forming the larger portion of the sward, are lowland
grasses which climb up the mountains to great heights and are quiet at
home in their elevated habitat.
A common species is the Sweet Vernal-grass (Anthoxanthum
odoratum). It is a rather slender grass with perfectly smooth leaves,
and the flowering stems are terminated by a dense spike of brownish spike
lets. It is distinguished from all other grasses by its aromatic smell
which it imparts to the hay, giving it its sweet perfume.
Another common grass is the Wavy Hair-grass (Deschampsia
flexuousa), or rather its variety montana. It is a rather fine
plant producing a tuft of rolled up cylindrical leaves. It may be
distinguished by the fact that the slender branches of the panicle are
wavy, whilst the spike lets are a bright, shiny brown in colour.
The Purple Molina (Molinia caerulea) is an
abundant grass in the wetter moorland areas and often climbs up into the
alpine zone. It is a coarse, stiff plant, forming dense tussocks. The
panicle is long and narrow with erect branches and tiny spike lets which
are usually purplish in hue.
The Mat Grass (Nardus stricta) is a common
mountain grass and may be known by its densely tufted habit and its very
stiff, bristle-like leaves. The very slender spike is characteristic as
it consists of several, small spike lets arranged in two rows on one side
of the axis.
The Scottish alps are not wholly composed of species of
grasses, as a number of similar plants belonging to the Sedge Family (Cyperaceae)
are to be found, often in abundance, in the alpine pastures.
The sedges belong mainly to the huge genus Carex,
which contains over seventy-five British species. I will not attempt to
describe all the sedges to be found on the Scottish mountain sides, but I
will mention the more interesting alpine species of which there are about
twelve.
The sedges heave their flowers united into shapely
conical or cylindrical spikes of very compact structure. The individual
flowers are unisexual, that is, they contain either stamens only or a
pistol only. They consist of a small green or brown bract, in the axil of
which we find three stamens on weak filaments, or an ovoid ovary
surmounted by two or three stigmas.
In some cases only one spike is produced, with the male
flowers at the top, and the female ones below. In most cases, however,
several spikes are produced, each of which has the flowers arranged as in
the solitary spiked type, or the upper spikes are wholly male and the
lower ones are wholly female.
The flowers are pollinated by the wind, hence no nectar
is produced and the stigmas are feathery so as to present a large surface
to the pollen-laden wind.
The sedges usually have an underground, creeping stem
sending up leaves and flower stalks each year. The plants can be
distinguished from grasses by the fact that the flowers are all unisexual
and flower stem is three-sided. The leaves are usually harder and stiffer
in texture, the plants forming dense, low colonies.
Several of the alpine species are very rare and are
confined to the rocky ledges of precipices, but they help to make up the
fascinating alpine flora of our Scottish mountains.
The first two species I shall deal with are the Rock
Sedge (Carex rupestris) and C. microglochin. They both belong to
the solitary spiked type. The former is very rare and local, but has been
found from time to time on the mountains of Perthshire, Angus and
Aberdeenshire. It has a very short spike, less than one inch in length
and it is dark brown in colour. C. microglochin is confined to the
Ben Lawers area and has a tiny spike less than half an inch in length, of
a bright brown colour.
The next two species have several spikes, each of which
has both male and female flowers, the latter having only two stigmas.
C. lagopina is a very rare species which was once found on Lochnagar,
and may be found still on wet rocks on Cairn Toul and in one or two of the
Cairngorm corries. It has three or four oval-shaped spikes very close
together and of a brownish-green colour. C. canescens is a fairly
common plant in lowland bogs, but it has an alpine variety alpicola.
It has three or four small spikes at a distance from one another and of a
pale green colour. It is fairly well distributed on the higher mountains.
Three species are found with a mixed terminal spike,
with the male flowers at the base, and two or three lower spikes in which
all the flowers are female with three stigmas. They are C. alpina,
a very rare species to be found in the Ben Lawers area and in Clova, with
ovoid and black or very dark brown spikes and a green fruit; C. atrata
is a rather more common species, occurring on the higher mountains of
Perthshire and Clova, the Cairngorms, Inverness-shire and Argyll, with
black or dark brown cylindrical spikes and dark, shiny fruits; and C.
atrofusca, a very rare species found on Ben Lawers, with a male
terminal spike and female lower spikes in which the glumes are dark purple
with a pale midrib.
In the remaining six species, the upper one or two
spikes are male the lower ones female. C. saxatilis is another rare
species confined to the stony summits of Perthshire, Inverness-shire,
Argyll, Skye and Ross. It possesses a creeping, underground rhizome and
above ground scaly runners with terminate in tufts of leaves. The female
spikes are dark brown, the flowers possessing two stigmas. This
distinguishes it from the following species. It includes a
closely-related plant known as C. Grahami. It is confined to Ben
More and Ben Cruban in Perthshire and to Glen Fiagh in Clova.
A more common plant, C. rigida, is found on Ben Lawers,
the Cairngorms, Ben Nevis, as well as on most other high mountains. It is
scarcely six inches high, with flat, very rigid leaves. The glumes are
dark brown or black with a green midrib, whilst the female flowers have
but two, not three, stigmas.
Our last three species all have three stigmas. C.
Sadleri is a small tufted species with long, flat, broad, radical
leaves and four to six rich, dark brown spikes. It may be distinguished by
its long two-pronged fruit. It can only be found in Glen Callater in
Aberdeenshire C. vaginata is a rare plant, but fairly well
distributed on wet rock ledges on most of the higher mountains. It is a
close relative of the lowland C. panicea, which it closely
resembles. The last species, C. rariflora, is another very rare
alpine confined to Ben Lawers, Clova and the Cairngorms. It can be found
in alpine bogs, and may be distinguished by its dark brown glumes and the
small female spikes which are only one-third of an inch in length and bear
only six or eight flowers.
Besides the grasses and sedges which make up so much of
the Scottish alpine pastures, we have several alpine rushes which are to
be found in wet places on many of our higher mountains.
The first to be described are wood-rushes belonging to
the genus Luzula. They are the Spiked Wood-rush (L. spicata)
and the Curved Wood-rush (L. arcuata). The former is fairly widely
distributed. It is a densely-tufted plant with an underground creeping
stem. The leaves are flat and finged with white cottony hairs. The
flowers are produced in a dense, drooping spike nearly one inch in length
in the axil of a leafy bract. They are light brown in colour, the
individual flowers being constructed as in the Great Wood-rush (L.
maxima) (see Chap. XIII).
The other wood-rush is a much rarer plant. It is most
frequent in the Cairngorms, but is also found on Ben Nevis and in Ross and
Sutherland. It may be distinguished from the preceding by its almost
cylindrical leaves without white hairs. The flowers are produced in a
panicle of small clusters.
Four species of real Rushes (Juncus) are found
in the alpine areas. J. castanets is a rare plant confined to wet
places on the higher mountains of Perthsire, Angus, Inverness-shire and
Argyll. The plants have a tuft of a few, grass-like, channelled leaves
with one or two on the flowering stems. Each leaf ends in a fine
cylindrical tip. The dark brown flowers are produced in terminal heads,
which are solitary or in pairs, and are surrounded by numerous, leafy
bracts which overtop them. The fruit is a brown, shiny capsule nearly
twice as long as the perianth.
The commonest of the alpine rushes is J. trifidus,
which is to be found on most of the higher Scottish mountains in gravelly
and rocky places. It has an underground stem which creeps under the small
stones and gives rise to many very slender wiry stems. The small, matted
colonies of plants consist of withered stems, dead leaves and dust which
gradually make up a soil for higher plants. They produce two or three
very fine, cylindrical leaves which project above the stem like the prongs
on a fork. In the axil of the two upper leaves is a single, sessile
flower or a cluster of two or three flowers.
Of the two other alpine rushes, J. biglumis is
only found on Ben Lawers and one or two of the higher mountains of Argyll
and Skye, whilst J. trilliums is a more common plant fairly well
distributed on the higher mountains. They are very similar tufted plants
with short, grass-like, radical leaves. The short stems are terminated by
the flowers. In J. biglumis there are only two large, brown
flowers in the axil of a short, leafy bract. In J. trilliums
there are three or more flowers and the bract has no leafy tip. |
