Out last
large association of plants to be found in the Highlands is that of the
meadows and pastures in which plant life has been modified by the
interference of man, who has manured the soil, altered the drainage and
has unconsciously built up a very well-marked association.
The
meadows are found along the valley bottoms, where the rivers have built up
areas of silt and sand which are more fertile than the hillsides, and
where the land is sheltered from winds and storms by the high mountain
walls which hem them in. We find them again around the loch shores and at
their heads, where large patches of alluvial soil are to be found, and
also along the sea shores wherever a strip of low, fairly level land is to
be found and where there is shelter wherever a strip of low, fairly level
land is to be found and where there is shelter from the prevailing winds.
Naturally
meadowland is much more expansive in the large river valleys as in Tayside
and Speyside, and in the less mountainous areas as in the country around
Oban.
It is
bounded by the suitability of the soil and by the altitude. Very little,
if any, is to be found above 1,000 feet in the Highlands although in some
places as at Glen More in Rothiemurchus cultivated land and meadows are to
be found at or above the altitude. This spot, however, is well sheltered
by the mountains and surrounding forests. Above this height the long
winter and exposure make meadowlands impracticable.
The
meadows vary much physically. They are often marshy (especially those in
the valley bottoms) and intersected by many small streams. In this type of
meadow, marsh platns such as the Marsh Marigold, Marsh Orchids and
Lousewort are common and Rushes intrude among the grasses. These meadows
are too damp for oats or root crops and are usually grazed by cattle and
mown for hay in summer.
On the
drier soils and more sloping meadows which are well drained, the marsh
plants disappear and here Ox-eye Daisies, Buttercups and Yellow Rattle
predominate among the tall grasses.
On the
sandy soils washed down from the ancient moraines, as in Speyside, the
grass is short, owing to the dryness of the soil, and in these meadows
shorter and more tufted plants often of a xerophilous nature replace the
tall Buttercups; they include the Field Gentian, Harebell, Tufted Vetch,
Lady’s Fingers and Field Pansy.
In some
areas field of oats, roots and potatoes take the place of the meadows.
These fields have been made with infinite toil and patience by the
hard-working Scottish farmers and in spite of adverse conditions yield
quite good crops.
The
pastures are to be found along the foothills of the mountains. They are
rarely cut, and never manured, and are usually unfenced, being roamed by
cattle and sheep. Their upper limit is undefined as they gradually merge
into the moorlands and mountain pastures where grasses largely disappear
and heather, etc., take their place. The principal vegetation of these
pastures consists of grasses and sedges, whilst Orchids, Vetches and
Lady’s Mantle are widely distributed.
The
meadows and pastures are the homes of many interesting and beautiful
plants and include many of our commonest species. In these Highland
meadows one can study Nature beneath the shadow of the mountain tops,
whilst the mountain streams rush down with cheerful chatter though the
smiling meadows and the winds ruffle the heavy ears of the oats and waft
the scent of Clover and the sweet perfume of the Lady’s Fingers across the
valley. There, little white crofts hide in their encircling ring of
trees, and patient-eyed cattle graze contentedly, knee deep in the marshy
fields, whilst overhead the blue sky is flecked with soft, white, feathery
clouds against which the granite peaks stand out in fine relief. A lark
soars high, singing sweetly as it rises towards the life-giving sun, as if
praising it and thanking it for its warmth and light.
Harebell
(Campanula rotund folia)
I will
commence my description of the various plants of the Highland meadows and
pastures with the beautiful blue Harebell.
Many of
my readers must be acquainted with that beautiful little Scottish glen,
Glen Nevis, which runs back, deep into the heart of the Lochaber, between
the massive buttresses of Ben Nevis and the graceful peaks of the Mamore
Forest.
It is a
lovely glen, whether it be in the lower reaches, where it widens out into
grassy meadows with here and there in a white croft, and the river Nevis
gliding gracefully between its tree-lined banks as it sweeps on to the
nearby sea. Or beyond, where the mountains close in upon the river which
dashes down tumultuously in its deep, granite gorge, the waters boiling
and roaring among the boulders; or where the Heather moors and Myrtle bogs
fill the valley and cataracts dash down the steep mountains side from the
fastness of Ben Nevis and his giant brothers; or where we again find a
tiny croft amid green, boggy meadows, yellow with Marsh Merigolds, watered
by the beautiful cascade which tumbles in sparkling foam down the
precipitous sides of Sgur a’Mhaim.
Yes, Glen
Nevis is beautiful, and especially in summer when the Yellow Saxifrage
hangs down n golden tufts beside the waterfalls, and the Orchids fill the
meadows and bogs with their colour and sweet perfume and the mountain air
is fragrant with Bog Myrtle, whilst the lovely, deep-pink Dog Roses smile
from every bank and in every crevice right down to the water’s edge sway
the pale blue bells of the Harebell. Long may the peace and loveliness of
this glen remain untouched by the ugly hand of so-called civilization and
progress.
Here in
Glen Nevis the Harebells are a deeper blue than elsewhere. They seem to
have set out to rival the blue of the Lochaber sky, that pale blue washed
by a thousand stoms of rain until it is clear and brilliant.
Let us
top for a moment and examine this delightful flower whose bright bells
dance in the soft breeze on every bank, and in the mossy crevices of the
rocks and give so much delight to the passer-by.
The
Harebell, or as it is called popularly, the Scottish Blue-bell, is well
adapted to exposed situations in grassy pastures and on banks. Its wiry
stems are tough enough to withstand the ferocity of the wind, whilst its
fine, narrow leaves offer little surface to the air, and hence reduce loss
of water by transpiration.
The
rootstock is very slender and creeping, and well adapted to penetrate deep
into the fissures of rock in search of moisture.
A rosette
of radical leaves, which dies away at the time of flowering, crowns the
rootstock. They are long-stalked and are heart-shaped, often quite round,
hence the scientific name, rotundifolia.
From the
rosette arise the flowering stems which may attain a height of eighteen
inches to two feet in good soil and sheltered localities, where it is
often branched (in meadows of Speyside I have come across many plants
which exceeded that height) or it may hardly attain six inches in poor
soil or on exposed situations (I have found them in the Lower Cairngorms
with a simple stem no more than four inches high and crowned by one large
flower).
The
flowering stems are covered with many long, very narrow leaves, which are
quite different in appearance to the radical leaves. The reason for the
differences in the leaves is this. Early in the year, before the plant
has sent up its flowering stems, it is surrounded by grasses, they are in
full sunlight and exposed to the wind. Hence the plant has no need of the
broad shade leaves, but required leaves which present as small a surface
as possible to the sun and wind.
The
flowering stems support a raceme of a few large, drooping, pale blue
flowers which may be reduced to a solitary terminal bloom. They are very
beautiful structures and a detailed study of them will show one how
marvelously they are adapted to their insect visitors.
Their
drooping position protects the pollen from the rain and makes it
impossible for crawling insects to enter and pilfer the pollen without
fertilizing the flower.
Each
bloom consists of a wide-mouthed bell formed by the five united petals.
The nectarines are situated at the base of the style near the bottom of
the bell. If the flower that we are examining is near the point of
opening, we shall find that the style is completely covered by the five
stamens which at this time are united at their margins. The anthers form
a closed ring around the upper portion of the style.
In older
blooms we shall see that the style has commenced to lengthen and is
pushing through the anther ring. As the style is covered with many hairs,
the pollen s wept out of the anthers and carried upwards beyond them. At
this stage the three stigmatic surfaces are pressed close together to
guard against self-fertilization.
As soon
as the anthers have shed all their pollen they curve back and downwards
from the style. An insect visiting the flower at this stage will become
dusted with pollen from the stylar brush as it tries to reach the
nectarines. If the anthers have not curled back already, the slightest
touch of the corolla by the insect is enough to make them do so.
At a
still later stage the three stigmatic flaps curve back to expose their
receptive surfaces at the entrance to the bell. An insect arriving from
another flower will leave pollen from that flower upon the stigmas. On
withdrawing any danger of self-fertilization is averted by the fact that
the receptive surfaces are on the upper sides of the flaps.
The depth
of the bell and the fact that the nectarines are at its base prove that
the nectar is conserved for long-tongued insects. Large bees, of which
blue is the favourite colour, and butterflies are the flower’s chief
benefactors.
The
stylar brush mechanism is common among flowers, being found throughout the
great Composite Family as well as in the Bellflower Family.
Thus we
see that these lovely flowers, which charm the eye, are not beautiful just
to delight our fancies or to beautify the countryside. Their function is
much more prosaic, as they are simply to attract the bees and so obtain
cross-pollination, the ultimate goal aimed at by all plants.
The fruit
of the Harebell is also a very clever structure consisting of an ovoid,
semi-transparent capsule. At its base we shall notice three or four
small, triangular valves closed by a small flap. In dry weather these
flaps open and on being shaken by the wind the seeds are jerked out to a
considerable distance, but in wet weather the flaps close and protect the
precious seeds from damp.
As often
happens among blue flowers, pure white blooms are frequently found. The
depth of blue is also very variable, for in southern England the blue is
often very pale and faded, but in the Highlands it is bright and often
deep.
The
Buttercups (Ranunculus)
One of
the loveliest sight in these islands in early summer is that of the
meadows, golden with Buttercups. A sign of bad farming, some say, and
this may account for the rarity of buttercup filled meadows in the
Highlands, which are so meticulously farmed that the Buttercup has a hard
struggle to live in the hay crop. A plant so hardy and well equipped for
success in life is very difficult to exterminate and golden banks,
roadsides, waste ground and badly kept meadows give point to this
statement.
The
Buttercup is a lovely flower and one of our most popular wildings, for it
commences to bloom when the warm sunshine tells us that summer has
arrived, when the cuckoo proclaims from every wood that life is
worth-while and the swallows dive and glide over the meadow lands in the
sheer joy of living.
Few
people are aware that the flower commonly known as the Buttercup is not a
single species. The Common Buttercup of the meadows is Ranunculus
acris, a very abundant and handsome plant; but besides this species we
have two other very common species which are found in similar situations.
They are the Bulbous Buttercup (R.bulbous), remarkable for its
bulbous stock, and the Creeping Buttercup (R. repens), a very
common and mischievous weed whose creeping stems make it very difficult to
eradicate.
We will
commence with the Common Buttercup, of which a description will illustrate
how admirably the Buttercups are suited to life in the meadows. This fine
plant is a perennial with long, fibrous roots which push deep down into
the soil to the lower moister layers where they are sage from winter cold
and summer drought.
The
leaves, which at first are all radical, have long stalks which carry the
leaves up above the surrounding grasses and allow them to obtain the
maximum quantity of light. These radical leaves keep competitors at a
distance, as in their shade they have little chance to thrive. The
leaves, which are hairy on both surfaces as a precaution against excessive
transpiration, are cut into five or seven lobes, which are themselves cut
into three much indented lobes and are fairly broad and wedge-shaped.
From the
summit of the stock arises the tall, erect, branching, flowering stem
which may attain two or three feet in height in good soil, although in
poor soil and mountain situations it may only attain six inches. In the
Larig Ghru, at 2,500 feet, I have found it with flowering stems only one
or two inches high.
The tall
stem carries the flowers well above the surrounding vegetation and so
makes them more conspicuous. It is clothed with shortly stalked leaves
which are cut and divided like the radical leaves; the segments, however,
are very narrow. This is to keep down transpiraton by exposing as small a
surface as possible to the hot summer sun and dry winds.
The
flowers are arranged in loose panicles at the termination of long stalks.
They are large and of a bright yellow, the petals having a very glossy
surface, and are surrounded by five hairy sepals which are of a yellowish
green colour and are spreading.
The large
colonies formed by this plant make the bright flowers very conspicuous and
in early summer the meadows are transformed into a sea of gold which
attracts insects from far and wide.
At the
centre of the flower is a rounded mass of pistils around which are several
rings of stamens. At the base of each glossy petal is a tiny, golden cup
in which nectar is secreted. Insect visitors alight on the centre of the
flower where they must leave imported pollen upon the carpels, and as they
turn to suck the nectar from each tiny cup they become dusted with pollen
from the myriad anthers, which they will transfer to the next flower
visited. Thus cross-pollination is achieved. It must be obvious,
however, that very often pollen from the stamens of a flower will fall
upon its own pistils and self-fertilization will occur. This, however, is
not a disadvantage as a large number of pistils occur in each flower and
the chances of all of them being self-fertilized is remote.
Honey-bees, bumble-bees, m;ining-bees, flies and hover-flies are attracted
in large numbers to the beautiful blooms.
The whole
plant is impregnated with a very acrid juice which is a great protection
against herbivorous animals. Cows will carefully at the grass all around
the Buttercups, but leave them severely alone, thus giving the lie to the
old idea that cows fed in buttercup meadows gave yellower butter than
those fed in meadows where Buttercups were lacking.
The
Creeping Buttercup (R. repens) is another plant which by its method
of growth has made a great success in the struggle for existence. It is
very common in meadow lands where it form large colonies that prevent the
growth of grass and by their creeping habit encroach continuously upon the
surrounding herbage.
It forms
rosettes of radical leaves which in dry situations may be close and
compact, the leaves being small with short stalks. In more favorable
situations the leaves are on fairly long stalks, but they are always more
densely arranged than in the Common Buttercup.
The
leaves are composed of three stalked segments which are each divided into
three dissected segments. The stem leaves are few and often reduced to
three lanceolate, entire lobes.
From the
midst of the radical leaves long, creeping stems, called runners, push out
into the surrounding herbage and whoever the nodes touch the soil they
root and form fresh rosettes of leaves and thus new plants are formed
which, in time, also send out runners. Thus large colonies are formed
which prohibit the growth of grass or other plants within their confines.
The leaves form large carpets in much the same way as in the alpine carpe
plants that we have already studied.
The
rosettes send up long flower stalks which are seldom more than one foot
high and produce several flowers, much like those of the Common
Buttercup. The habit of forming colonies makes the flowers very
conspicuous as the flowering stems of many rosettes are close together,
thus giving a large number of blooms in a small area.
They are
pollinated in the same way as the flowers of the Common Buttercup.
The
Bulbous Buttercup (R. bulbous) is remarkable in that the base of
the stem is enlarged to form a kind of bulb or rather a corm. This
Buttercup is the first to be found in flower. This is explained by the
fact that the corm is a storehouse of food and allows the plant to
commence growth without waiting for its fibrous roots to commence active
work. Hence it gains a good start over allied species.
Its
leaves are rather small, the radical ones being produced on fairly short,
hairy stems and forming a close rosette. They are divided into three
fairly symmetrical segments.
The
flowers, which are large, are produced on stalks about one foot high. In
this species the sepals hang downwards from the petals. They are
fertilized as in the foregoing species.
Globe
Flower (Trollius europaea)
This
beautiful plant is a fairly common one in the lower mountain pastures and
moist meadow lands, especially in the western Highlands where large masses
of these lovely yellow flowers are often to be encountered alongside
streams and in damp, boggy places.
I first
became acquainted with the Globe Flower at the entrance to Glencoe, where
large colonies of these plants beautified the scarred, wet edges of the
road. Since then I have found it in many places on the hillsides of
Lochaber and Ardgour and have had ample chance to study its peculiar
flowers.
The Globe
Flower is a member of the Ranunculus Family and resembles the Buttercups
in the form of its leaves. The perennial rootstock is crowned by a
rosette of radical leaves on long stalks. The are lobed, very much like
the leaves of the Common Buttercup, but are devoid of hairs as we should
expect in a moisture-loving plant. From the summit of the rootstock rises
the simple flower stalk, which attains a height of about one to two feet,
and possesses two or three small sessile leaves, in form much like those
of the radical leaves. The flower stalk is terminated by a single large
yellow flower which is shaped like a globe, with no visible entrance into
the interior.
We shall
find that the bright yellow exterior is really formed by the sepals which,
as in the case of the Marsh Marigold, are the conspicuous part of the
flower and do the advertising. These sepals, which may be from ten to
fifteen or even more in number, overlap one another, and are curved in
such a fashion that their tops meet in the centre to completely close the
globe. If we dissect away the walls of the globe, we shall find that they
enclose a number of flat yellow objects which are the real petals. They
are equal in number to the sepals and actually function as honey-glands
which secrete a large amount of that sweet substance. These are followed
by the many rows of stamens, whilst in the centre of the flower we find
the several carpels which are quite free from one another.
Now one
would be quite right to ask why a flower which has not entrance for bees
and butterflies should secrete such an abundance of honey?
Well, let
us go to a clump of these lovely flowers and watch the blooms closely. If
we do so, we shall see many tiny flies crawling over the sepals and
disappointing between them into the centre of the flower, whilst others
appear from the interior, from time to time, covered in pollen and fly
away to other blooms.
These
little flies are the pollen carriers and it is for them that the flower
has so carefully concealed its treasure. As they move around the inside
of the flower they will leave pollen on the stigmas, thus causing
cross-pollination. Naturally, pollen from its own stamens will also be
carried to the stigmas by the wanderers, but as long as a small amount of
imported pollen is deposited on the stigmas, cross-fertilized seed will be
set.
The
closed bloom protects the nectarines from rain, which in the mountains is
a great advantage. Many insects, especially beetles, bit holes in the
sepals and steal the nectar, thus upsetting the flower’s plan.
This,
then, is yet another fashion by which cross-pollination is obtained, and
it must leave us with a sense of wonder to see in what diverse ways plants
have evolved, hand in hand with their particular insects visitors, and how
assiduously they conceal their treasure for their particular benefactors.
THE
LEGUMINOUS PLANTS OF THE MEADOWS AND PASTURES
The
Highland meadows are the home of several interesting plants belonging to
the Leguminous Family.
We have
already described several members of this great family in the preceding
chapter and some of them, like the Tufted Vetch and the Tuberous Bitter
Vetch, may often be found in the meadowlands.
The
leguminous plants to be here described are all very common plants and may
be found over a wide area. They are the Bird’s Foot Trefoil (Lotus
corniculatus); the Lady’s Fingers (Anthyllis vulnerary); and
two clovers, the Red Clover (Trifolium pratense) and the White
Clover (Trifolium repens).
The
Bird’s Foot Trefoil (Lotus conriculatus)
This
plant is very common, very widely distributed and very variable. It may be
found in meadows and pastures on waste land, in rocky places, on heaths
and moorlands, and well up the mountain sides living under conditions of
drought and poor soil or in well-manured and wet meadows.
It is a
beautiful little plant in spite of its lowly habit and abundance. Its
racemes of bright yellow flowers vary from bright red through orange and
deep yellow to a pale lemon colour, the changes of colour often being
perceptible in the various racemes of the same plant.
The
Scottish species are the common form Lotus corniculatus, Lotus
crassifolius, a common form in dry, sunny regions and possessing more
fleshy leaves than the common type, and Lotus major, often found in
moist, rich meadows.
The
Bird’s Foot Trefoil possesses a long, deep-striking tap-root, which
attains the moister regions unaffected by the heat of summer sun or the
cold of winter. This root gives rise to several stems which usually creep
along the surface of the ground where vegetation is sparse, or they may be
erect in grassy regions. In rich regions the stems become almost erect
and tall, thus overtopping the more luxuriant herbage of these places.
The stems produce many pinnate leaves consisting of five ovate leaflets.
In the more luxuriant varieties, however, they become larger and thinner,
while in those inhabiting dry, stony or sand places they become broad,
glaucous, and often of a thick texture, this being a drought-resisting
device.
The
flowers are produced on long stalks, much longer than the leaves, and
consist of dense umbels of bright yellow flowers. They are very
conspicuous and attract many of the smaller bees for whom the flowers are
specially adapted. (see Broom, page 164)
After
flowering the blooms wither and long straight pods follow them, which are
arranged like the claws of a bird’s foot, and have given the plant its
popular name.
The
Lady’s Fingers (Anthyllis vulneraria)
This
beautiful plant is quite common in low meadows among grasses, and is
sometimes cultivated as a fodder plant. Certain meadows as one approaches
Loch-an-Eilean from Aviemore, are filled with this plant and the beautiful
hay-like perfume is noticeable at a long distance upon the soft mountain
breeze. This perfume attracts the bees from far away to feat at its pale
yellow blooms and transfer the vital pollen dust.
The
Lady’s Fingers is a perennial plant and has a tufted rootstock which sends
up semi-erect stems, which in luxuriant plants may attain one foot in
height. These stems are clothed with pinnate leaves. The lower ones
usually have a long terminal leaflet, the other leaflets being reduced to
a small size. The whole plant is covered with long silky hairs which, by
controlling excess transpiration, fit this plant to inhabit dry pastures.
The flowers are produced in close umbels, two of these umbels being found
close together at the termination of the stems, just above a leafy
much-cut bract. The flowers are usually of a pale yellow colour, but vary
to bright yellow, and even deep red. They are surrounded by a soft hairy
calyx which persists after flowering to protect the seeds pods.
THE
CLOVER
Before we
leave the description of the Leguminous plants of the Scottish meadows, we
must devote a short section to the two common clovers to be found there.
They are
the Red Clover (Trifolium pratense), which is a very common plant
in the meadows, on roadside banks, and in the lower pasturelands, and the
White Clover (Trifolium repens), a very common meadowland plant.
The Red
Clover possesses a perennial rootstock which, however, is not of long
duration. The roots are remarkable for the fact that, as with many
members of the Pea Family, bacteria live in certain nodules upon them.
These bacteria are able to obtain nitrogen from the air contained in the
soil and pass it on to the roots of the plant which in turn feed and lodge
the bacteria. For this reason clover is often grown in fields and then
ploughed in, in order to enrich the soil. This mutual help arrangement,
know as symbiosis, is quite common in the plant world and we have already
met with this phenomenon in the account of the Heaths (Chapter XIV).
The
rootstock sends up rather weak which may be semi-erect or spreading. They
produce trifoliate leaves on long stalks, the leaflets being ovate and,
like the stems, covered with hairs. The stems are terminated by a dense
head of purple-red flowers
The
clover has aimed at conspicuousness in the same manner as the Composites
by arranging its flowers into a close compact head. This also means that
one bee may fertilize many florets at one time instead of a single bloom,
as would be the case if only one flower were produced.
Each
flower has a small tubular calyx, surmounted by short teeth and covered
with silky hairs. The corolla possesses a long tube and is a miniature
pea flower in form.
The
flowers are constructed for pollination by bees. The inset alights on the
wing petals which adhere to the keel. Its weight depresses the keel,
forcing the stamens and pistol to protrude. As the stigma projects beyond
the anthers it touches the insect’s body first, thus receiving any pollen
which it may have brought from another flower. Thus cross-pollination is
assured. Other insect such as butterflies visit the flowers, but are
rarely able to cross-pollinate them.
The White
Clover also possesses a tap-root. The stems are long and creeping and
send out roots at the nodes. Leaves are produced at each node and in time
a single plant may colonize a large area. Its lowly habit saves from
destructive by sheep and cattle, and hence, in pastures, it often thrives
exceedingly, the soil being concealed by its trifoliate leaves.
As in the
Red Clover, the roots possess tubercles containing bacteria, and these aid
the plant in obtaining nitrogen.
The
trifoliate leaves are too well known to need description, and are
remarkable for their powers of movement. At night the two lateral
leaflets move in towards each other until their two surfaces touch, and at
the same time the upper leaflet bends downwards and covers the other two,
so that they are protected from cold and dew. In cold weather similar
movements take place during the day.
The
flowers are similar to those of the Red Clover, but are pure white or
white tinged with pink. They are pollinated in the same way as those of
the Red Clover.
COMPOSITES OF THE MEADOWS
Several
Composites are found in the meadows and pastures. They are all very
common plants in the lowlands, but several of them such as the Sneezewort
(Achilla Ptarmica ), the Dandelion (Taraxacum officinale)
and the Melancholy Thistle (Carduus heterophyllus) are found at
considerable elevations.
Dandelion (Taraxacum officinale)
Probably
no flower in the world is know to so many people and loved by so few as
the Dandelion.
This
common plant, inured to every hardship, is to be found in every part of
the world, whether in the rich cultivated fields and gardens of the
lowlands, on dry sterile moorland and bleak hillsides, in wet places by
streams and in boggy meadows, or high up on our mountain sides, competing
with the Saxifrages and other alpine plants for existence.
Of all
the numerous places in which I have found the Dandelion none was more
romantic than that at 3,000 feet behind the jagged edge of Aonach Dugh,
that forms a rugged rampart to wild Glencoe, and from which the eye sweeps
back over miles of heather moors to the shining waters of the Blackwater
Loch and to the great peaks of Ben Nevis and the Mamore Forest Mountains.
To the south one sees the fearsome precipices of Bidean Mor, clear cut in
the sparkling air, and one can look down with awe into the deep chasm
where lies peaceful Loch Etchachan, surrounded by great precipices, sheer
drops of hundreds of feet to the boulders below. Here amid such beautiful
scenes and sublime surroundings, I found many clumps of our humble garden
weed, the Dandelion. Many times since, on finding the golden blooms in
some corner of my garden, I have stopped to think of their many cousins
starring the green turf in the beautiful spot high above the ‘Glen of
Weeping’.
The
Dandelion, by its tenacity, has spread across the Glove from Arctic to
Antarctic in the wake of European colonists, and in spite of every means
to arrest its growth, it has thrived so well as to be a pest in every
country where it has been introduced.
If the
Dandelion had been a rare plant, the beauty of its large yellow heads
would have been praised alike by artist and gardener, but like many common
things most of us pass it by without even giving it a thought.
But the
Dandelion is well worth a very careful study. For this plant, which has
crossed the boundless oceans in its stride, climbed mountain chains and
traversed whole continents in its world conquest, is adapted as few plants
are for the struggle of existence. We shall find much food for deep
thought and careful reflection in the story that can be read by those who
wish to read it.
In the
Highlands this plant can be found almost everywhere, but naturally it
attains its finest development in the meadows and pastures of the valleys
and lower lands.
Why has
the Dandelion been able to live and thrive under so many conditions of
climate, of soil and of altitude?
In the
first place, it possesses a very deep-striking tap-root which goes well
down into the soil, where frost and cold cannot harm it, and where drought
holds no terrors. This tap-root is a reservoir of energy, which lies
dormant in the soil throughout the winter, but with the return of milder
weather it is at once ready to start into growth, using its stored energy
until such time as the leaves and roots can co-operate to obtain food.
The root also contains a bitter juice which renders it very unsavory to
grubs and animals, hence it is safe from their attacks.
In the
second place, all the leaves of the Dandelion are radical and are arranged
in a perfect rosette, each leaf being so placed with regard to the others
that it obtains a maximum quantity of light. At the same time the
flatness of the rosettes results in the fact that the lower surfaces, with
their vital stomata, are facing the soil, from which moisture is always
arising and thus transpiration is reduced. The rosette formation keeps
competitors at a distance, as life is impossible beneath the shade of the
spreading leaves. They also present a large surface on which dew is
condensed at night and this, running down the prominent mid-ribs, drips
off near the centre of the rosette to moisten the soil around the
tap-root. The same is true of rain, which is also directed towards the
centre of the rosette. The closeness of the leaves to the soil also saves
them from the force of the wind. These leaves, like the roots, are very
bitter and are left alone by animals, but man, however, sometimes uses
them for salads, disguising the bitter flavour with salad creams and
vinegars.
In the
third place, the arrangement of the flowers is a potent reason for the
abundance of this plant.
From the
midst of the rosette of leaves arises a leafless flower stalk, which
attains a height of about one foot. It is a hollow tube, the
architectural form the best able to withstand the force of the wind and to
support the large flower head.
The stalk
is crowned by a single golden head of flowers, which is often one and a
half inches in diameter. This head consists of an involucre of two or
three rows of lanceolate bracts, the outer ones recurved to act as a
barrier to crawling insects
The
flower itself consists of many florets, all of which bear a strap-shaped
golden petal. The floret consists of this strap-shaped petal united at the
lower edges in the lower part to form a tube of about half an inch in
length. The tube is surrounded by a ring of silky hairs which are the
rudiments of the sepals, whilst within, at its base, we find the
nectarines. The stamens are inserted on the tube and their anthers are
united at the edges to form a closed cylinder which projects about half an
inch from the floret tube. The stigma is at first situated inside the
ring of anthers, and hence cannot be seen when the floret first opens.
After
opening the style commences to elongate and pushes its way through the
anther ring. At this time the stigma lobes are pressed closed together so
that self-fertilization is impossible. The style below the stigmas is
hairy and as the anthers open inwards and gradual lengthening of these
style causes the hairs to seep the pollen out of the anthers like a brush.
When the stigmas are clear of the anthers they open and become receptive.
Each ring of florets opens in succession, commencing from the exterior.
An insect
visiting the head for nectar or pollen will naturally fertilize many
florets with transported pollen in one visit. As the flowers remain open
for a long time, they may be visited by many insects, and hence it is
highly probable that all the florets will be cross-pollinated. As the
floret tube is not deep and the nectar rises high in the tube, it is
available to quite short-tongued insects and so attracts many visitors.
Flies of many species, hover-flies, short-tongued bees, beetles and
butterflies all visit the flowers in great numbers. Small wonder that a
flower which presents its gifts so freely, and remain open for so long,
should come first in popularity with the insect world and hence set a
great quantity of cross-fertilized seed.
After
flowering the head closes, the maturing seed being protected from damp by
the involucres. The airs elongate and with the withering of the corolla
form a silky parachute above the seed. When it is mature the head opens,
the hairs spread out and the parachute opens to sail away and deposit the
seed far from the parent plant. Thus the Dandelion spreads its frontiers
farther and farther, crossing seas, mountain chains and deserts in its
stride.
Thus we
see that the Dandelion owes its success in life not to any haphazard
chance or a lucky succession of chances but simply to the fact that it is
adapted in every fashion to make the best of life, and attracts as many
insect visitors as possible so that plenty of strong cross-fertilized seed
is set.
Small
wonder it is common from pole to pole and up to the limit of vegetation on
the mountain sides.
Long-rooted Cat’s Ear (Hypochaeris radicata)
The
meadows are the home of many Composites, which are of very common
occurrence and are very widely distributed. We have already described the
Dandelion, and the present subject is in many ways very like it.
The
Long-rooted Cat’s Ear is, as its name suggests, a very deep rooted plant
with a tap-root of great length in which is stored nourishment for an
early start as soon as the warmer days commence. This long toot also taps
the deep moisture-laden layers of the soil and the plants is thus able to
withstand long periods of drought.
In the
spring the rootstock sends out many long, blunt, lanceolate leaves which
are deeply indented with large, blunt teeth. They form a very close
rosette performing the same function as in the case of the Dandelion. The
leaves are covered on both surfaces with short, almost bristly hairs which
protect the leaves against excess transpiration.
It
commences life well adapted to combat adverse conditions and competitors.
No wonder that it is so common in dry pastures, on banks and in meadows.
From the
midst of the radical leaves arise long robust flower stalks which are
devoid of leaves, but possess several small scales which take their
place. They attain a height of two feet, and are usually once branched,
although in luxuriant specimens they may branch several times and may send
up eight to twelve main stems.
One may
probably wonder why the Cat’s Ear has not economized by shortening its
stem like the Dandelion, which in spite of its short simple stems has made
such a success in the life struggle. The reason is to be found in the
flowering seasons. The Dandelion flowers early in the year whilst the
meadow herbage is snort and its stems are well able to clear the
surrounding vegetation. The Cat’s Ear, however, flowers in summer when
the herbage is tall and if it possessed short stems in flowers would be
hidden, so it has adopted long flower stalks which enable the flowers to
bloom well above the surrounding grasses.
Each
branch is terminated by a large bright yellow head of flowers. It
possesses an involucre of many bracts arranged in two or three rows and
covered on the outer surface with several rows of hairs, white below but
often black or dark brown above. These bracts protect the flower against
damp whilst in bud, and against crawling insects when in bloom. The upper
part of the flower stalk, immediately below the flower, is enlarged and
hollow, probably to strengthen the stem in order to hold the large flower
head erect.
The head
itself is composed of a vast number of strap-shaped florets arranged as in
the case of the Dandelion, and of a very similar construction, with the
same method of fertilization, etc.
As the
hone rises high in the floret tube it is accessible to quite short-tongued
insects. It is visited by a vast number, such as flies, hover-flies,
bees, wasps and butterflies, all supping at its abundant table.
I watched
a large drone-fly alight upon one of these flowers and pass its tongue
quickly along the hairy styles, licking off the pollen and at the same
time pollinating many florets. During the course of quite a short space of
time many different species of insect visited the flower and all its
mature florets must have been cross-pollinated in that time.
The
flower heads close at night, and also in dull weather, thus protecting the
pollen from rain and dew. They flower for a considerable length of time,
seven to ten days being quite common.
Thus when
we examine even the commonest of plants, we find that they are arranged
with an amazing nicety and ingenuity. Every hair has a significance and
the whole flower is arranged in complete harmony with its environment, its
season of flowering and its insect visitors. Even the most cynical must
admit that in no other place in this world is the hand of the Creator more
evident than in the domain of flowers.
After
flowering the head closes and the petals wither away. At the same time
the fringe of hairs surrounding the floret tube lengthens and becomes
brownish in colour. The hairs are pinnate like a feather. When the seed
is mature the head opens again and the wind detaches the seeds and away
they go for miles on the breeze before they descend to earth. No wonder
that the Cat’s Ear, like most members of the Composite Family, has
conquered the whole of the Northern Hemisphere from the Pacific to the
Atlantic.
CRUCIFEROUS PLANTS OF THE PASTURES
Three
members of the Cruciferous Family (Cruciferae) can be found in the
Highland pastures. One, the Hairy Rock Cress (Arabis hirsuta), is
to be found throughout the area and may climb to 3,000 feet. It prefers
drier pastures, especially those on limestone, but may also be found on
dry, sandy pastures along the sea-shore.
The other
two prefer damper places, especially in stony areas. The Hairy Bitter
Cress (Cardamine hirsuta) is quite a common plant and may be met
with high up the mountain sides. The Wavy Bitter Cress (C. flexuosa),
a very similar plant, prefers shady, damp places, and for this reason may
be looked for amid rock patches, on the sides of ditches and in the shade
of small trees or shrubs. It also is well distributed and has been found
at high altitudes.
The Hairy
Rock Cress is a biennial and if we cam across the plants in summer, we
should find that some of them consisted solely of rosettes of leaves,
whilst the others were in flower. The former, which are young plants,
will not flower till the following year, whilst the latter will die once
the flowers have faded and the seeds have set.
The leaf
rosettes are pressed close to the ground where the mouths of grazing
animals cannot get at them. They consist of several oblong leaves with a
few teeth around the margin and a covering of short, stiff hairs. If we
dug up a plant, we should find that it possessed a longish tap-root which
acted as a food store during the winter when the leaf rosettes were
covered by snow.
In the
following season they send up a tall, very stiff, erect, flowering stem
which never branches. It is clothed with small, hairy leaves, which stand
erect upon the stem and clasp it by tiny auricles. It is terminated by a
raceme of small, white flowers, which are typically Cruciferous in
structure and are pollinated as in the case of the Cuckoo Flower (see
Chapter XVII).
The
flowers are followed by erect pods about one and a half inches long, and
these give the plant a very distinctive appearance.
The Hairy
Bitter Cress is an annual and, in spite of its abundance, is quite an
attractive little plant with its fresh, green, daintily-cut leaves, each
segment of which is rounded and seated upon a tiny stalk. They form a
close rosette from the base of which fine roots push down into the soil,
and it is remarkable how quickly the plant develops quite an extensive
root system.
As soon
as the leaves are well developed, a flower stalk (or in luxuriant
specimens, many) is sent up. A few leaves are formed upon it and they are
terminated by a raceme of small white flowers.
The pods
are about one inch and their two sides curl up elastically when dry and
throw the seeds for some distance. In dry situations the plants finish
their life cycle in the course of two or three months, but in damp places
they keep flowering throughout the summer, new flower stalks arising from
axillary branches.
The Wavy
Bitter Cress is a perennial, but usually behaves as it were a biennial.
It is very similar to the preceding, but the stems are flexuous and more
leafy and it is larger in all its parts. It may be distinguished by the
fact that it has six stamens, whereas the former has only four.
The
flowers of both species are pollinated as in the case of the Cuckoo
Flower. They are, however, often self-pollinated, as they are
inconspicuous and the stigma stands at the same height as the anthers.
PRIMULAS OF THE PASTURES
Cowslip
(Primula veris)
The
Cowslip is to be found in the lower pastures throughout the Highlands,
although it is missing from some areas. We have five Primulas in Britain,
three of which are found in Highland Scotland. Of these our present
subject is perhaps the most beautiful, and it is a general favourite with
all flower lovers. The short, grassy pastures bedecked with Cow-slips,
Orchids and other spring flowers are a delight to the eye and a pleasing
reminder that winter, with its frost and snow, is well behind us.
Like the
Primrose, it possesses a short, perennial, underground stock giving rise
to a rosette of ovate leaves which contract abruptly towards the base, the
lower portion consisting of a broad mid-rib bordered by a narrow, leafy
margin. They are green and wrinkled above, but the under-surface is
covered with a minute, pale down. The waxy covering, characteristic of
the Primrose, is wanting in this species, which is also almost hairless.
Each
plant sends up one or two tall erect, flower stalks which are terminated
by an umbel of several flowers. As in the case of the Primrose, some
plants produce long-styled flowers, others short-styled flowers.
In the
short-styled flowers, the corolla consists of a narrow tube about one inch
in length, surmounted by a cup-shaped chamber in which the five sessile
stamens are found. The cup is bordered by five small deep golden yellow
lobes, each of which has a deeper yellow mark at its base to act as a
honey-guide to insect visitors.
The
globular ovary is situated at the bottom of the corolla and is surrounded
by a ring secreting nectar. The pin-headed stigma, supported on a slender
style only reaches half way up the tube.
In the
long-styled flowers, the cup-shaped chamber is salver-shaped and twice as
deep, the tube being correspondingly shorter, whilst the mark at the base
of the lobes is almost orange. The stamens are situated in the lower part
of the salver, in a position corresponding to that of the stigma in the
short-styled flowers. The long style places the stigma at the entrance to
the salver in a position corresponding to the stamens in the short-styled
flowers.
The
mechanism to ensure cross-pollination is thus the same as in the case of
the Primrose, but the flowers are very sweetly perfumed and, by their
umbellar arrangement, the bee can visit more flowers in a given times in
the Primrose.
Scottish
Primrose (P. scotica)
Few
people know the far, northern shores of Scotland where , from the tops of
the wild, lonely cliffs of Sutherland, one looks north over the
white-capped Atlantic which breaks in clouds of spray far below. It is a
strange feeling to know that between one and the Arctic ice there is
nothing but that turbulent waste of water. One feels that here, indeed,
is the Ultima Thule of the ancients. Here on this savage, yet strangely
beautiful coast, one could really believe that one was at the end of the
world and that beyond was nothing. In winter when the fierce
north-westerly gales are blowing that feeling must be enhanced a
hundredfold.
The
cliffs tops of this far-away land are covered in grassy pastures and here,
if we are lucky, we may find one of the rarest and most isolated of
British plants, the Scottish Primrose. It is only to be found along the
northern coast of Sutherland and Caithness, and again in the Orkneys. It
is believed to be a variety of the Bird’s-eye Primrose (P. farinosa),
but that plant is found no farther north than the Pentland Hills. The
Scottish Rift Valley and the Highlands separate them, and it is impossible
to say to what vagary of the Ice Age we owe this strange distribution.
It is a
small but lovely plant, with a short, perennial rootstock, hidden deep
down among the grass roots and covered in winter by their withered leaves
and stems.. The leaves are produces in a close rosette and are remarkable
for the thick, mealy texture of the under surface. This is due to a waxy
excretion which prevents water settling on the lower surface of the leaf
and so blocking the stomata. This is a necessary precaution for a plant
growing in damp surroundings and with its leaves in close contact with the
underlying soil and herbage.
About ten
flowers are produced in an umbel at the summit of a short stalk, often
only two inches high. They are beautiful, deep purplish-blue in colour
with a yellow centre, but are only about three-eighths of an inch across.
The flowers have the usual Primrose construction, but the entrance to the
tube is glandular.
When the
flowers open, the stamens are found attached by short filaments to the
sides of the corolla-tube. The pistil has a short style, but this
elongates until it is at the same length as the stamens. Bees visit the
flowers, but in their exposed habitat they must often escape visitors.
This does not matter as the elongation of the style makes self-pollination
possible.
The
strange fact remains that P. farinose is dimorphic, in the same way
as the Primrose and Cowslip, yet P. scotica has only one type of
flower. This variation has come about from the scarcity of insect
visitors, which has made the flower much more dependent on
self-pollination. For this same reason, the flowers are reduced in size
and number.
Here we
meet a fascinating example of isolation causing the evolution of a new
species. It is quite certain that this species has evolved from a
community of P. farinose which may have been isolated during the
Ice Age. As this community was out of all contact with any other similar
one, it has bred away from the type. It gradually lost its dimorphic
condition until a point was reached where self-fertilization became the
rule. Any cross-pollination effected by bees would then only be between
closely related individuals. Continued inbreeding would result in the
fixing of certain characters in the race, so that today P. scotica
is already well removed from P. farinosa.
HIGHLAND MILKWORTS
Three
species of Milkwort are found in the Scottish pastures. They are
Polygala serpyllacea, a common plant in most pastures where there is
no lime in the soil and often climbing the mountains to 3,000 feet; the
Common Milkwort (P. vulgare), a more common plant in lower
pastures; but as it requires lime in the soil it is absent wherever the
soil is acid; the third species , P. dubium, is a common plant in
dry, turfy pastures and on grassy sand-dunes, but confined to low levels.
They are
all creeping, weak herbs which only attract our attention when they are in
flower. They are remarkable for their great variability and this is
nowhere more apparent than in the colour of their flowers. Bright red,
blue and white bloomed plants may be found within a small area and the
various colours are connected by all kinds of intermediate tints.
If we dug
up a plant of the Common Milkwort, we should find that it had a short,
almost woody rootstock from the summit of which arose several half erect
or weak creeping stems which might attain one foot in length in long grass
or in the moister areas.
The
leaves are crowded towards the lower part of the stems and are here
rounded in outline, farther along the stems they are alternate, more
widely spaced and become lanceolate in form. They are quite smooth, often
with a glaucous appearance.
The small
flowers are produced in fairly dense, terminal racemes and are remarkable
for their peculiar structure. If we examined a flower, we should see what
at first appear to be two large oval petals surrounding the flower. These
tow structures, however, are sepals in spite of the fact that they are
colored and veined with deeper hues. We should also find three tiny green
structures round the base of the flower. These are sepals of the usual
form.
If we
carefully pulled the sepals away, we should see that the centre of the
flower is occupied by a tubular structure which is open at the back and
terminated by two oval, erect lobes. The front of the tube is occupied by
a strange horizontal structure from which project upwards many tiny
finger-like processes. The whole is very complex, being composed in part
by petals and in part by the filaments of the eight stamens which are
united as in the Pea family.
The
anthers are found at the entrance of the tube, behind the frilled
platform. They are arranged on the summit of the tube in two groups of
four each. The two cells of each anther coalesce to form a single chamber
and the anthers look like tiny pockets opening at the top.
The
rounded ovary is terminated by a funnel-shaped style which has a
spoon-like extremity, the stigma being situated on a little recurved lobe
behind it.
The
spoon-like tip is so placed that when the anthers open the pollen falls
into it. The flowers are visited b the bee, which pushes its proboscis
down to the nectary at the base of the tube, but in so doing it touches
the sticky stigma on which any transported pollen is left. The proboscis
becomes covered by the sticky substance and, on withdrawing, the pollen on
the spoon-like extremity of the style adheres to it.
In spite
of this elaborate contrivance to obtain cross-pollination, the flowers are
often self-pollinated through the pollen running back along the spoon-like
process and coming in contact with the stigma.
The seeds
are distributed by ants. Each seed has a tiny tubercle containing soil
and this has an attractive function for the ants, which carry off the
seeds to their nests to feed their young and also to replenish their food
stores. Many seeds, however, are dropped en route and thus the Milkwort
is distributed far and wide over the hillsides.
Polygala
serphyllacea is a very similar plant, but may be distinguished by the fact
that its stems are flexuous and the lower leaves are opposite. P.
dubium is believed by many authorities to b but a variety of P.
vulgare. |