Rock and Scree Communities

Rock and Scree Communities

The exposed slopes near the steps leading into the Alpine Garden are used to cultivate plants which would otherwise be found much higher up the mountains. These have been grown from seeds in the Botanical Gardens Innsbruck and were collected from their natural habitat. In their habitat, the alpine level, they are perfectly adapted due to their low, cushion-form growth. This form protects them from ultra violet rays during the summer months and from drying out, as well as from snow and ice-storms in winter. In order to use the short period of vegetation of less than 100, days many of these plants already store the flower buds for the next spring in autumn. Three life forms, i.e. pillow plants, the rosette plants and the tussocks have survived particularly well in the high alpine regions. Various cushion types (flat cushion, hemispherical cushion, spherical cushion) spread through consistent growth and regular branching.
A typical representative of cushion plants is the Moss Campion (Silene acaulis), a clove plant. It is a plant that grows dense, mosslike cushions, and which at blossoming time is covered with stemless, individual red flowers. The species grows in the Alps in various communities, in the silicate rocks these are found up to 3600 metres above sea level and extend from Arctic Europe to Asia and Northern America. Among the rosette plants slow growth of the main shoot ensures that the distances between the leaves remain small, and a dense leaf spiral (rosette) results.
This is illustrated by the Paniculate Saxifrage (Saxifraga paniculata) . During periods of great heat, drought and cold it can close its evergreen, fleshy rosettes and thus protect itself more. This enables it to grow in places blown free of snow. Common in the Alps it also grows in arctic Europe and Northern America.
 
Among the saxifrage plants the Pyramidal Saxifrage (Saxifraga cotyledon) is the most conspicuous. The large rosettes of up to 15 cm diameter form offshoots, but die after flowering. The fleshy, tongue shaped leaves are chalk encrusted and have gnarled, serrated edges. The pyramid shaped, leaning flower panicles grow to 60cm in length and consist of up to 100 individual flowers. It is common in northern Europe and the Alps, where it settles in damp silicate crags up to 2500 m. In the garden a somewhat smaller subspecies from the Montafon, Vorarlberg was planted.
Most of the grasses are typical tussock plants. Along a short basic axis a large number of branching side shoots form a dense plant stem - the tussock.
Standing tussocks derive their strength from a dense stock of basal lateral buds. Wandering tussocks spread after stocking by forming shoots. Even combinations of these life forms like cushion forming rosette plants were adaptations to locations in the Alps.
The Edelweiss (Leontopodium alpinum), probably the most well-known alpine plant, settles in chalk ground up to more than 2800 metres. The sought-after star shaped flower is a pseudo-flower, formed by white felt-like leaves, surrounding the yellow-green flower heads in a star-shaped form. Our Edelweiss is not an indigenous alpine plant, but an immigrant from the Siberian steppes and only settled here after the last Ice Age. The main distribution area of this species of the family of aster plants lies in Asia, where 30 different species are to be found. The white pubescence, also to be found on other mountain plants, fulfils a twofold purpose: on the one hand it provides a protective air cushion that reduces evaporation - a typical process of adaptation to drought and wind. On the other hand, the light-reflecting white upper bracts act as a signal for honey seeking insects. By nature the Edelweiss, as is frequently assumed, would not only inhabit steep, inaccessible rock faces but would also inhabit lower alpine meadows. As the Edelweiss has been sought for centuries by man it has only survived in exposed and inaccessible regions in the Alps.

Ein typischer Vertreter der Polsterpflanzen ist das sileneacaulis_cenisia.jpg, ein Nelkengewächs.Es ist eine in dichten, moosähnlichen Polstern wachsende Pflanze, die zur Blütezeit oft völlig von den stengellosen,roten Einzelblüten bedeckt ist. In verschiedenen Sippen besiedelt diese Art die Alpen, im Silikatgebiete steigt sie bis auf etwa 3600m und ist über das arktische Europa bis nach Asien und Nordamerika weit verbreitet. Bei den Rosettenpflanzen bleiben durchlangsames Wachstum des Haupttriebes die Abstände zwischen den Blättern kurz, eine dichtstehende Blattspirale (Rosette) ist die Folge.

Dies ist deutlich am Trauben-Steinbrech (Saxifraga paniculata) zu erkennen.Bei großer Hitze, Trockenheit oder Kälte kann er seine immergrünen, fleischigen Rosetten schließen und sich somit zusätzlich schützen. Dies ermöglicht ihm auch auf im Winter schneefrei geblasenen Stellen zu siedeln. In den Alpen häufig, besiedelt auch er das arktische Europa und Nordamerika.

Unter den Steinbrechgewächsen ist der Pracht- oder Strauß-Steinbrech (Saxifraga cotyledon) wohl die auffälligste Erscheinung. Die großen, bis zu 15cm breiten Rosetten, bilden zwar Ausläufer, sterben aber nach der Blüte ab. Die dicken, zungenförmigen Blätter sind leicht kalkbekrustet und am Rande knorpelig gezähnt. Die pyramidenförmigen, überneigenden Blütenrispen werden bis zu 60cm lang und bestehen aus bis zu 100 weißen Einzelblüten. Er ist in Nordeuropa und den Alpen verbreitet, wo er feuchte Silikatfelsspalten bis 2500m besiedelt. Hier im Garten wurde eine etwas kleiner bleibende Unterart aus dem Montafon/Vorarlberg gepflanzt. Die meisten Gräser sind typische Horstpflanzen. Entlang einer kurzen Grundachse wachsen zahlreiche sich verzweigende Seitentriebe und bilden einen dichten Pflanzenstock – den Horst. „Standhorste“ erstarken durch dichte Bestockung aus basalen Seitenknospen, „Wanderhorste“ breiten sich nach der Bestockung durch Ausläuferbildung aus. Auch Kombinationen dieser Lebensformen wie polsterbildende Rosettenpflanzen sind Anpassungen an Standorte im Hochgebirge.
Das Edelweiß (Leontopodium alpinum), wohl die bekannteste Alpenpflanze, besiedelt vorwiegend Kalkböden bis über 2800m. Der begehrte Blumenstern ist eine Scheinblüte, gebildet aus weißfilzigen Hochblättern, welche die gelbgrünen Blütenköpfchen sternförmig umschließen. Unser Edelweiß ist keine alteingesessene Alpenpflanze, sondern ein Zuwanderer aus den sibirischen Steppen und ist erst nach der letzten Eiszeit zu uns gekommen. Das Hauptverbreitungsgebiet dieser Gattung aus der Familie der Asterngewächse, liegt in Asien, dort gibt es etwa 30 verschiedene Arten. Die weißfilzige Behaarung, die man auch bei vielen anderen Gebirgspflanzen findet, erfüllt einen doppelten Zweck: zum einen entsteht zwischen den Haaren ein unbewegter Luftmantel, der die Verdunstung vermindert, eine typische Anpassung an Trockenheit und Wind. Zum anderen wirken die lichtreflektierenden weißen Hochblätter als Signal für honigsuchende Insekten. Von Natur aus würde das Edelweiß, wie oft angenommen, nicht nur steile, unzugängliche Felswände besiedeln, sondern ist eine Art tiefer gelegener Bergwiesen. Da der Mensch ihm aber seit Jahrhunderten nachstellt, konnte es sich in vielen Teilen der Alpen nur an solchen Extremstandorten behaupten.

Rock and Scree Communities Similarly well-known and also threatened is the Bear's Ear (Primula auricula)This Primula has a barrel-shaped, multi-branched root stock and - depending on its habitat - grows from 5 to 30cm high. The inverted egg shape, fleshy leaves have a very gnarled edge and are intensively mealy. The yellow gold flowers have a strong smell. They spread beyond the Alps to the Carpathian Mountains, particularly in the Southern Alps less mealy and smelling regional variants are to be found. The Bear’s Ear can settle from 2900 metres to the valley floor (as in Gnadenwald near Hall - about 700 m above sea level). Towards the end of the 16th century the Primula became part of garden culture and as a fashionable plant could be bought in thousand different varieties. In particular in England an Auricula mania arose around 1900.

Much-loved representatives of the species Gentian in garden culture include the group of Stemless Gentian which, in popular opinion, are not distinguishable from each other, but at least 6 different species are distinguished by the botanist. The Broad-leafed Gentian (Gentiana acaulis))is always found on acid soil.From its pale green leaf rosette the stemless, dark blue bell flowers grow to a height of 6 cm. The similar Clusius’ Enzian (Gentiana clusii) is distinguished by its spiked leaves and calyx and beyond that prefers lime soil. Both species spread from the Pyrenees to the Alps and the Carpatian mountains to an altitude of 3000 metres. The flowers of both species are erroneously depicted on the labels on Gentian schnapps bottles. The original, rare schnapps is made from the tall Yellow Gentian, where about 100 kilos of root are required for one litre of schnapps. Due to unchecked uprooting and plucking, but in particular through the use of chemical/artificial fertilizers it has become rare or even extinct in some regions.
This also applies to the well-known Spring Gentian (Gentiana verna) and at least three similar hardly distinguishable species popularly termed Cobbler's Nail (“Schusternagele”). The deep blue star-shaped flowers of the Spring Gentian stand up to 10 cm above the ground level leaf rosette. It inhabits scree and patchy meadows on chalk up to 2900 metres above sea level. The somewhat smaller Short-Leaved Gentian (Gentiana brachyphylla) grows on poor chalk soils, particularly in the Central Alps. Particularly in autumn we find similar but densely flowering, red violet coloured gentians in the Alps. All of these are very short-lived and frequently only annual, which on the whole is very rare among alpine plants. Nearly all these small species close their flowers during cold or cloudy weather.
A further horticulturally widespread plant is the Alpine-Aster (Aster alpinus).It is a plant that grows to 20cm and nearly always has a single-headed leafy and hairy stem. The flowers themselves are conspicuously large (up to 5 cm) with external blue violet tongue shaped flowers, and golden yellow disc-shaped flowers inside. In its various species the aster inhabits the European mountains, the Caucasian Alps extending to Siberia and North America.

Rock and Scree CommunitiesThe Yellow Genipi/Wormwood also belongs to the daisy family, represented by ten species in the Alps. The Glacier Wormwood (Artemisia glacialis) is to be found on silicate but rarely also chalk slate.It is an aromatically smelling herbaceous perennial that grows to a height of 20 cm and is covered in grey pubescence. Its leaves are formed like hands with three or five lobes and up to 5cm long. The gold yellow flowers form a multiple head at the end of the stem. This species, occurring only in the Western Alps (endemically), inhabits crevices and pioneer meadows up to 3000m. Wormwood inhabits similar locations (e.g. Artemisia umbelliformis), having spread more widely from the Pyrenees to the Alps. It is distinguished by less segmented leaves and less densely positioned, clearly stemmed light yellow individual flowers. It is often found together with the Digital Leaved Wormwood (Artemisia genipi). Its leaves are covered densely with hair and grey felt, the inconspicuous flower heads forming a thick, nodding grey brown head. The Wormwoods are rich in bitters and essential oils and are esteemed as a therapeutic and spice plant. As they were also used to produce liquor and vermuth they have become rather rare.
A reliable companion in self-proliferation the alpine poppy is to be found along the steps. These are up to 20cm tall small cushions and frequently short lived perennials with pinnate leaves and large individual flowers. The yellow Rhaetian Poppy (Papaver rhaeticum) inhabits the area from the Eastern Pyrenees to the South-Western Alps, east of where the white flowering species occur, such as Bursers Apine Poppy (Papaver burseri).As the species are frequently bastardize a number of bastards with different colour tones have been created. All kinds have a strong pile root and are characteristic settlers of screes spreading from the Pyrenees to the Balkan Peninsula.
It co-occurs on lime screes with Alpine Toadflax (Linaria alpina), a figwort. It is a glabrous plant that grows to 15cm and frequently forms small loose cushions. The species that has a life of two years forms its flowers in a short, separate bunch. The crown of its flowers is blue violet with a long spur, some forms having a saffron yellow lower lip. As a typical scree plant it neither inhabits meadows nor crevices: the European mountains are its home.

Rock and Scree CommunitiesOf the orpine family (Crassulaceae) some have settled well above 2000m, like for example the houseleek genus, which is represented by ten species in the Alps. Generally on silicates we find the Large—Flowered Houseleek (Sempervivum grandiflorum)native to the southwest Alps.The dark green, short pointed leaves form dense rosettes up to 15 cm diameter. From these the star shaped rich yellow flowers sprout on a shaft that is up to 30cm long. The equally yellow flowering Wulfen's Houseleek (Sempervivium wulfenii) looks very similar, distinguished by the intensely blue ringed rosette leaves and is native to the Eastern Alps. On lime poor soil in all regions of the Alps we find the Cobweb Houseleek (Sempervivum arachnoideum). It forms substantially smaller, red rosettes that are covered with white woolly hairs like a spider’s web. All houseleek species have water tissue inside the leaves, which is covered by a rough surface skin and sunken crevices preventing evaporation. All species form relatively long runners (stolons), daughter rosettes that in the course of time separate, roll away and root elsewhere. This is particularly marked in the case of the Allonis Houseleek (Jovibarba allionii) which was planted in large numbers at the top end of the steps. The yellow brown spherical rosettes have a red hue and bear a light yellow flower extending up to 20 cm. The species is only to be found in the South Western Alps on lime and silicate. Due to the numerous daughter rosettes attached directly to the mother plant they are easily cultivated. After flowering, the rosettes die and the particularly fine seed (1g has more than 50000 corns) is spread far by the wind. More than thirty different species can be found from the central and south east European Alps and the Caucasian Mountains, and as they easily bastardize, large numbers of hard to distinguish natural hybrids are formed. Due to intensive horticultural breeding more than 100 species are available.
The Roseroot (Rhodiola rosea) belongs to the same family. It is a multi-branched perennial that grows to 40 cm and has turnip-like roots. The lance shaped leaves are fleshy, serrated and cumulate towards the flower. The yellow or red flowers stand in terminal cymes. It inhabits damp, humus rich soil, crevices and alpine herb fields on lime and silicate up to 3000m. The name ‘roseroot’ refers to the rhizome which smells of roses, which was frequently used as a carminative (radix rhodiae). This type, the only representative of the species in the Alps, extends from Europe over Siberia to Greenland.

Rock and Scree CommunitiesBelonging to the buttercup family (Ranunculaceae) approximately 6 partly very similar kinds of common Pasque Flower or Anemone inhabit the Alps. The Spring Pasque Flower (Pulsatilla vernalis) grows only in acid soils. Due to its very early period of flowering, immediately after the snow thaw it can only be recognized by its infrutescens. The tufted perennial grows to 15cm tall. The leathery, pinnate ground leaves spend the winter pressed close to the ground. New ones are only formed after flowerin. The flowers are originally only bell-shaped and nodding, later they are spread and upright. Inside they are white, outside pale violet and have dense down in gold brown. The stem of the hairy tousled fruit grows to 40cm. Each of the pointed seeds is provided with one up to 5 cm long hair which acts as a propeller and which will later dig the seed into the earth through hygroscopic movements. The plant inhabits dry, stony ground and sedge meadows above 2000 metres and can be found in Northern Europe, the Pyrenees, the Alps and Bulgaria. Other species, like the Mountain Pasque Flower (Pulsatilla montana) flower substantially later. They are distinguished by flowers which are black violet inside and hoary grey outside and fine forked leaves. They grow on very dry silicate and chalk soil up to 1800 metres and grow from the Pyrenees and the Southern Alps to the Balkans. Always on lime ground we find the white flowered Alpine Pasque Flower (Pulsatilla alpina), which grows from the Pyrenees to the Caucasus and the red violet flowers Haller's Pasque Flower (Pulsatilla halleri), of the Eastern Alps. Exclusively on acid soil we find the Sulphur Anemone (Pulsatilla alpina ssp.apiifolia). Being 40 cm tall, it grows taller than the other species and is the only alpine cowbell to bear sulphur yellow flowers. All cowbell types are light-seeking and prefer dry neglected grassland. They vanish abruptly when fertilizer is used, particularly chemical fertilizer.

Rock and Scree Communities