Blunt-leaved willow

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Blunt-leaved willow
Blunt-leaved willow (Salix retusa)

Blunt-leaved willow ( Salix retusa )

Systematics
Rosids
Eurosiden I
Order : Malpighiales (Malpighiales)
Family : Willow family (Salicaceae)
Genre : Willows ( Salix )
Type : Blunt-leaved willow
Scientific name
Salix retusa
L.

The stump-leaved willow ( Salix retusa ) is a species of willow ( Salix ).

description

Illustration from Atlas of Alpine Flora
Female kitten
Male kittens
Habit and leaves

Vegetative characteristics

Salix retusa is a deciduous, prostrate dwarf shrub or espalier shrub with short, crowded, winding and coarse branches. The bark of the 5 to 30 centimeter long branches is olive green to brown, smooth and thin. The roots are strongly developed and reach deep between the crevices in the rock.

The leaves are divided into a petiole and a leaf blade. The petiole is 2 to 3 millimeters long. With a length of 5 to 20 millimeters and a width of 5 to 8 millimeters, the simple leaf blade is obovate to broadly ovate, usually with entire margins and shiny on the top. The autumn leaves are bright yellow. The dried twigs and leaves have a strange and intense scent of valerian.

Generative characteristics

The stump-leaved willow is dioecious, separate sexes ( diocesan ). Ten or more flowers are found in upright catkin-shaped inflorescences that shoot at the same time as the leaves . The male inflorescences are yellow and only 1.5 inches long.

The capsule fruit opens in half and contains numerous seeds. The very small seeds have a dense pappus .

The number of chromosomes is 2n = 76, 114, 152.

Similar species

Similar to the blunt- leaved willow is the common- leaved carpet-willow ( Salix serpillifolia Scop. ), Also called common- leaved willow . In the past it was often regarded as a subspecies of the stump-leaved willow ( Salix retusa subsp. Serpillifolia (Scop.) Arcang. ), Has much more densely leafy branches and significantly smaller leaves and a tightly closed, grass-like growth that the stump-leaved willow never shows. It occurs in the same habitat as Salix retusa in the Alps, but often inhabits more sunny locations and lower altitudes than Salix retusa .

distribution

The blunt-leaved willow belongs to the alpine species of the European glacial flora and is also a glacial relic . It is also an arctic-alpine representative of the mountain flora that has no arctic distribution (European arctic-alpine species). Their occurrence is limited to moderate and subtropical high mountains. The natural distribution area is in the European alpine high mountains : Pyrenees , Alps , Apennines , Jura . Carpathian Mountains , Dinaric Mountains . In Bulgaria , Salix retusa is only found on the summit of the Ibar in the Rila planina.

It occurs in the Alps and pre-Alps at altitudes of mostly 1700 to 2500 (1260 to 2640) meters, in Bavaria up to 2470 meters, in Tyrol from 1700 to 2640 meters, in Valais from (1260 to) 1500 to 2500 meters, in Switzerland Jura from about 1200 to 1700 meters. In the Allgäu Alps, it rises at altitudes from 900 meters to well over 2000 meters.

In the arctic regions of Eurasia, Salix retusa and Salix serpillifolia are replaced by Salix nummularia Anderss. (Arctic Europe and Asia, in eastern Siberia and south to the Altai and Mongolai), as well as through Salix rotundifolia Trautv. (Arctic Europe and Asia, as well as in East Asia southwards to the Okhotsk region and Kamchatka).

Locations

The blunt-leaved willow forms prostrate dwarf willow trellises in snow-rich locations, where it spreads anemophilically . It is a type of light and grows very slowly. She reaches a great age in the process. Locations are rocky, sunny habitats of the subalpine and alpine level. Typically, it settles here carts around and in limestone snow soils and based block and limestone rubble heaps with long-lasting snow cover . The mildly humus stone and rubble soils are rich in bases and mostly calcareous. It also grows on bare rock where it reaches deeper crevice substrates with its strong roots. In the Alps, Salix retusa grows at altitudes between 1600 and 2900 meters.

The blunt-leaved willow can, together with the white silver arum ( Dryas octopetala ), colonize initial locations in the periglacial of the high mountains. It is thus a pioneering species that, for example, fortifies striped alpine soils in the Alps. Striped soils develop as strips of stone running diagonally towards the valley, which from the clearing of the stones on the surface of the ground and through capillary sucked in water, will cause fine soil material in the cavities under the stones. Striped soils are sorted by gravity and also show a zoning that indicates a progressive soil development via the succession of plant communities. First, Dryas octopetala and Salix retusa fasten the middle rubble, which is brought to a halt, with roots stretched like a rope and over 1 meter long. Then the upholstered sedge ( Carex company ) settles .

As an ecological type, it is one of the rubble deckers, which forms smaller solid islands in the moving stone by spreading with its sprouts, branching out densely and thus holding the moving rock. Other espalier shrubs, such as Salix reticulata , Dryas octopetala , Arctostaphylos uva-ursi , Saxifraga oppositifolia and Gypsophila repens, belong to the same type of plants that mostly consolidate fine debris . Salix retusa forms the stairs described above in the rubble.

The increased heat reflection of branches and leaves near the ground is described as an advantage of the espalier-like growth habit.

Plant sociology

The stump-leaved willow is a characteristic species of the plant-sociological association Salicion retusae. Two associations were originally separated from areas of south-east Europe: the Soldanello-Salicetum retusae Horvat 33 (= Salix retusa-Carex nigra -Ass.) On coarse-block heaps that attach to limestone rocks (including in the Čvrsnica, Bjelašnica, Vranica and Durmitor), as well as the Saicetum retusae-reticulatae macedonicum Horvat 36 from Macedonia (Jakupica and Šar Planina). Common to the association are among others: Soldanella alpina ; Anemona baldensis , Carex nigra , Ranunculus montanus , Polygonum viviparum , Carex kitaibeliana u. a.

After Ivo Horvat had set up the association Salicion retusae for the Dinarides in 1960, corresponding associations of the Alps were placed in the association Soldanello alpinae-Salicion retusae in 1999 by Thorsten Englisch . In 2005 Bošjan Surina examined the associations for the Southeast Alps in which he ruled out the following associations: Salici retusae-Geranietum argentei (Julian Alps), Homogyno discoloris-Salicetum retusae (Krn in the Julian Alps as well as the Carnic Alps, Karawanken and Kamnik), Salicetum retuso-reticualatae (Lienz Dolomites and Carnic Alps, Monte Baldo, Belluno Dolomites, Bernina), Potentillo brauneanae-Homogynetum discoloris (Julian Alps and Karawanken).

Boštjan Surina and Branko Vreš were able to identify an association outside the high mountains for deep depressions in the karst plateaus of Slovenia, the Drepanoclado uncinati-Heliospermetum pusilli Surina & Vreš , within the association Salicion retusae . This association grows in the Slovenian Karst in the Snežnik and Trnovski gozd in deep glaziokarst depressions and is characterized by temperature inversion and a cool, humid, rainy climate by the deciduous moss Sanionia uncinata and the small ray seeds ( Helispemra pusillum ). In addition to Sanionia and Heliosperma , only the stump-leaved willow is a characteristic of the association, which is stagnant on consolidated periglacial rock heaps . Viola biflora , Carex capillaris , Chrysosplenium alternifolium , Carex atrata , Polygonum viviparum and Festuca nitida appear as other accompanying species , while among the mosses Oncophorus virens , Campylium stellatum , Polytrichum alpinum , Pohlia elongata subsp. elongata and Orthothecium rufescens are most common. Only Norway spruce , lashed alpine rose and large-leaved willow can be found in the shrub layer, or these fail completely due to the extreme climatic conditions.

literature

Web links

Commons : Blunt-leaved Willow ( Salix retusa )  - Collection of images, videos and audio files

Individual evidence

  1. ↑ a b c d Čedomil Šilić 1988: Atlas Drveča i Grmlja. In: Priroda Jugoslavije , Volume 1, 3rd edition, Svjetlost, Sarajewo, p. 69.
  2. ^ A b Gustav Hegi : Illustrated flora of Central Europe. Volume III / 1, 3rd revised edition, Paul Parey 1981, ISBN 3-489-59020-1 . Here p. 78.
  3. ^ Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas. 8th edition. Verlag Eugen Ulmer, Stuttgart 2001, ISBN 3-8001-3131-5 , p. 310.
  4. ^ Gustav Hegi : Illustrated flora of Central Europe. Volume III / 1, 3rd revised edition, Paul Parey 1981, ISBN 3-489-59020-1 . Here p. 79.
  5. ↑ Vladmir Stevanović, Snežana Vukojičić, Jasmina Šinžar-Sekulić, Maja Lazarević, Gordana Tomović, Kit Tan: Distribution and diversity of Arctic-Alpine species in the Balkans . Plant Systematics and Evolution, December 2009, 283.219, (PDF)
  6. ↑ Veska Roussakova, online database on the EUNIS habitats in Bulgaria: Alpine calciphilic dwarf-shrub communities near melting snow-patches [1]
  7. ^ Gustav Hegi : Illustrated flora of Central Europe. Volume III / 1, 3rd revised edition, Paul Parey 1981, ISBN 3-489-59020-1 . Here p. 76.
  8. ↑ Erhard Dörr, Wolfgang Lippert : Flora of the Allgäu and its surroundings. Volume 1, IHW-Verlag, Eching near Munich, 2001, ISBN 3-930167-50-6 , p. 409.
  9. ^ Wilhelm Lötschert: Plants at border locations. Gustav Fischer, Stuttgart 1969. Here p. 38
  10. ^ Wilhelm Lötschert 1969: p. 29
  11. ^ Ivo Horvat, Vjekoslav Glavac, Heinz Ellenberg 1974: Vegetation Southeast Europe . Geobotanica Selecta (Ed. Reinhard Tüxen), Vol. IV, Gustav Fischer, Stuttgart. ISBN 3-437-30168-3
  12. ^ Ivo Horvat, Vjekoslav Glavac, Heinz Ellenberg 1974: p. 627
  13. ↑ Boštjan Surina 2005: Phytography and syntaxonomy of snow-bed Vegetation on calcareous substrates in the south-eastern alps: a numerical approach . Annales, Ser. hist. nat., 15/2, 223-238
  14. ↑ Boštjan Surina & Branko Vreš 2009: The Association Drepanoclado uncinati-Heliospermetum pusilli ( Arabiedtalia caeruleae , Thlaspietea rotundifolii ) in the Trnovski gozd Plateau (Slovenia, NW Dinaric Mts). Hacquetia, 8/1, 31-40.