Willows (genus)

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Pastures
Sal willow (Salix caprea), illustration

Sal willow ( Salix caprea ), illustration

Systematics
Nuclear eudicotyledons
Rosids
Eurosiden I
Order : Malpighiales (Malpighiales)
Family : Willow family (Salicaceae)
Genre : Pastures
Scientific name
Salix
L.

The willow ( Salix ) are a genus from the family of the pasture plants (Salicaceae) and about 450 include types . Their range extends over all parts of the northern temperate zone to the Arctic ; a few species are also native to the tropics and the southern temperate zone.

description

Vegetative characteristics

The willows (from Middle High German wīde , 'pasture', from Old High German wīda ' die Biegsame ', 'Salix species') are deciduous trees : trees , shrubs and dwarf shrubs . Among the willow types there are trees up to 30 meters high, but also dwarf shrubs that are only 3 centimeters high. The tree-like growing willow species are usually fast-growing, but also relatively short-lived. Willows form strong and well-branched roots and thus strengthen the soil. Willows are very prone to rash . That is why they were often used as pollard willows in the past and are now used to create energy forests. The well-drying wood of the willow is white or reddish. It is pliable, very light, tough and fibrous.

The leaves of the willows are very different. The shape ranges from almost circular to narrow and lanceolate. In many species the leaves are light green, and on the underside of the leaves - with a few exceptions - a more or less pronounced hairiness can always be seen. With all of them, the next sheet rotates by 144 °, i.e. 25 revolutions; every fifth looks in the same direction again.

Generative characteristics

Willows are dioecious and separate sexes ( diocesan ). The only exception is the weeping willow , which occasionally has female flowers in the male catkins . The flowers, which are gathered in fluffy catkins, are particularly noticeable on some types of willow and appear before or at the same time as the new leaves. Two differently shaped kittens can be observed: fat, egg-shaped, which contain the male anthers , and cylindrical, greenish colored, which bear the female scars. Both the male and the female catkins have two nectar glands at the base of each individual flower.

ecology

Young catkins of a sal willow ( Salix caprea )
Close up of a tree bumblebee collecting nectar from a catkins
A tree bumblebee collects nectar from a catkin

Most willows reproduce generatively through seeds. Many species can also reproduce vegetatively very well , such as the Salix fragilis : When there is a flood, branches are broken off and washed onto the bank where they can take root. The very good vegetative propagation is also used economically for propagation in tree nurseries or for engineering-biological slope and bank reinforcement.

Willows are dioecious separate sexes ( diocesan ), there are male and female individuals. In natural populations the ratio of both sexes is shifted in favor of the female specimen. Planted, vegetatively produced stands can also be purely male or purely female.

Depending on the species, the willow season begins to bloom very early in spring (March); late blooming species such as Salix pentandra bloom around May – June. Shifts due to the geographical location within a species are possible. The flowers are sought out and pollinated by bees and other nectar-collecting insects. For bumblebees , wild bees and honey bees , the early flowering species Salix caprea , Salix cinerea , Salix viminalis and Salix daphnoides are particularly important. The inflorescences of the willow are catkins . The herb willow , which is native to the insect-free tundra and the former mammoth steppe , is pollinated by the wind.

A wool floater looking for food on a catkins

After pollination, many-seeded capsule fruits develop from the female inflorescences . The seeds develop fairly quickly; the fruits are ripe after four to six weeks, spring up and release the seeds. The fruits of the laurel willow alone ripen in late autumn and release the seeds throughout the winter so that their seeds overwinter.

Willow seeds are probably the smallest native woody seeds, between 1 and 1.5 millimeters long and 15  millimeters wide, surrounded by a wreath of hair. Propagation occurs by the wind ( wind propagation ). Willow seeds belong to the hair flyers and umbrella flyers (trichometeorochory - meteorochory - anemochory ). The seeds can cover long distances. Large shrub or tree willows produce hundreds of thousands of seeds every year.

Due to its small size, the willow seed is only very poorly equipped with supplies for the seedling . The young plant is on its own and very susceptible to dehydration and competition for light and nutrients from other plants. It has no chance on densely vegetated areas. Willows are therefore decidedly pioneer plants . Due to the wide spread of the seed with the wind, they can quickly colonize areas free of vegetation ( alluvial land , forest fire or soil erosion areas), as there is no competition here. The seed germinates within 24 hours in good conditions. Under favorable circumstances, the plants can reach 0.3 to 1 meter in height in the first year. Fertility begins from the age of 4.

Tree willows rarely reach an age of more than 80 years.

use

Harlequin Willow (Hakuro Nishiki) Salix integra
New land settlement by Salix viminalis .

Ornamental plants

  • Real, Chinese or Babylonian weeping willow ( Salix babylonica ): This species, native to China , is extremely rare in Europe; it is only seldom planted here. In contrast, Salix × sepulcralis Simonk is often planted in parks and gardens . , the hardy bastard of the real weeping willow with the white willow ( Salix alba ). It is sold as Salix alba 'Tristis' or (incorrectly as) Salix babylonica ( see horticultural database ). The Chinese weeping willow is clearly distinguishable from this weeping willow with its yellow branches due to the brown branches.
  • Harlequin willow ( Salix integra Thunb. 'Hakuro Nishiki')
  • Corkscrew willow ( Salix matsudana Koidz. ): Ornamental plant from China.

Engineering biology

Living willows are an important tool in engineering biology . Because of their good rooting properties and the low demands on the soil, willows are often used to secure the soil, for example on slopes where there is a risk of slipping. For example, the Salix purpurea or, for more humid slopes, the black or large-leaf willow are suitable . It is important that they are not planted too close to each other, as otherwise they take away too much light from each other and sometimes degenerate and are therefore no longer able to secure the ground.

Willows are also often planted on streams whose banks are washed away. The white willow ( Salix alba ) and the broken willow ( Salix fragilis ) are very suitable for this, as they also thrive in very moist or even frequently flooded soils. The roots reach an average of about two meters deep.

Corkscrew Willow ( Salix matsudana )

Medicine and Medicine

The bark of the willow can be dried and brewed as a tea. It contains tannins , phenol glycosides , salicin and acylated salicin derivatives (including salicortin, fragilin, populin). Salicin, in particular, is converted in the body into salicylic acid , which is the basic substance of drugs based on acetylsalicylic acid (ASA). Salicylic acid has an antipyretic, analgesic and anti-rheumatic effect. The effect of willow bark (also: willow bark ) is stronger than it corresponds to the salicine content, therefore synergistic (supporting) effects of the other ingredients (especially the flavonoids ) are assumed. The willow leaves were used as a diuretic in the Middle Ages.

Branches and leaves

A basket weaver at work

The branches of willow, especially basket willow , are used as a material for weaving wickerwork ( e.g. baskets) and binding stave ware . Willow twigs used to be important in the building trade, in wattle walls, in braided infills in half-timbered structures and as a binding agent, the so-called widges in soft roofs made from reed or straw. The economic importance of willow weaving has declined sharply in the course of industrialization. In the past, willows were very often cut as pollarded willows in order to be able to harvest a high annual yield of young, flexible branches for weaving. In some areas (e.g. in Itzgrund ) this is still the case today.

A rule of thumb applies: the narrower the leaves, the easier it is to weave the willow. Willows with round leaves are often quite fragile.

The leaves of most types of willow are suitable as fodder.

Already for the Mesolithic are ropes and fishing nets assayed from Weidenbast.

Wood

Willow rod palace with rooted willow cuttings in Auerstedt , Thuringia

In Europe, the wood of the white willow ( Salix alba ) and various subspecies and varieties such as the weeping, cricket and yolk willow are used. It is used for various applications - in particular as round , industrial and sawn timber - and considerable amounts are used for energy (as biogenic fuel, e.g. in heating plants ). It is processed into chipboard and chipboard molded parts as well as peeled veneers and used as blind wood for furniture. Like poplar wood, it is also processed in the match industry; plywood , plywood for curved molded parts, chip baskets for fruit and vegetables and gift packaging are also produced from peeled veneer from willow . In England in particular, willow wood is the material used to manufacture the pickguards of cricket bats and has the task of dampening the impact of the ball, which can travel up to 130 km / h (the cricket willow, a subspecies of the white willow, got its name from this). Willow wood, like poplar wood, is increasingly not only produced in the forest , but also in short rotation plantations .

Pollard willows are a growth form of some types of willow that humans produce due to the use of wickerwork or green fodder (leaves).

.

Systematics

The genus Salix was established by Carl von Linné . A synonym of Salix L. is Pleiarina Raf.

Species native to Europe

White willow ( Salix alba )
Salix × sepulcralis

Trees and shrubs that can be taller than 4 meters:

Persian Willow ( Salix aegyptiaca )
Cabbage willow (
Salix herbacea )
Lapland willow ( Salix lapponum )
Polar willow ( Salix polaris )
Net willow ( Salix reticulata )

Small species up to 4 meters tall:

  • The high alpine species herb willow ( Salix herbacea) , reticulated willow ( Salix reticulata) and blunt-leaved willow ( Salix retusa) are grouped under the term “glacier willows”.

Species native to Asia

List of species native to Asia (selection)

Species native to North America

List of species native to North America

Species native to South America

hybrid

  • Foxtail willow ( Salix × alopecuroides exchange ): Salix fragilis × Salix triandra
  • Bastard-Ohrweide , Bastard-Kriech-Willow ( Salix × ambigua Ehrh. ): Salix aurita × Salix repens
  • Sea buckthorn-leaved willow ( Salix × hippophaefolia ): Salix triandra × Salix viminalis
  • Silk leaf willow ( Salix × holosericea Willd. Sensu Rechinger, Neumann, Skvortsov ): Salix cinerea × Salix viminalis
  • Fragile Laurel Willow ( Salix × meyeriana Rostkov ex Willd. ): Salix fragilis × Salix pentandra
  • Bush willow ( Salix × mollissima Hoffm. Ex Elwert ): Salix triandra × Salix viminalis
  • Multi-veined willow ( Salix × multinervis Döll ): Salix aurita × Salix cinerea , 3 to 4 meters?
  • Reichhardt-Weide ( Salix × reichardtii A.Kern. ): Salix caprea × Salix cinerea
  • Pale willow , high willow ( Salix × rubens closet ): Salix alba × Salix fragilis
  • Blend willow ( Salix × rubra Huds. ): Salix purpurea × Salix viminalis
  • Kübler willow ( Salix × smithiana Willd. ): Salix caprea × Salix viminalis

symbolism

In Europe, branches with catkins from the Sal willows have replaced the palm fronds , which are blessed on Palm Sunday in the Catholic Church (incorrectly "palm consecration"). The pussy willows are therefore often also called " palm kittens ".

In China , the willow is a symbol of spring, sexual desire, and girl joy. A brothel is understood as a flower-and-willow yard .

See also

literature

  • Gregor Aas : Systematics and biology of native willows (Salix ssp.). In: Reports from the Bavarian State Institute for Forests and Forestry. Volume 24, 1999, pp. 5-9 ( PDF file; 39 kB ).
  • Georg Franz Hoffmann: Historia salicum iconibus illustrata . Crusius, Leipzig 1785 (digitized version) .
  • Elvira Hörandl, Florin Florineth , Franz Hadacek: Pastures in Austria and adjacent areas. Self-published engineering biology and landscaping, University of Natural Resources and Life Sciences, Vienna, 2002, ISBN 3-9501700-0-6 ( preview ).
  • Dagmar Lautenschlager-Fleury, Ernst Lautenschlager-Fleury: The pastures of Central and Northern Europe: Identification keys and species descriptions for the genus Salix L. 2nd, revised and renewed edition. Birkhäuser, Basel / Boston, 1994, ISBN 3-7643-2994-7 .
  • Karl Heinz Rechinger, John R. Akeroyd: Salix. In: TG Tutin, NA Burges, AO Chater, JR Edmondson, VH Heywood, DM Moore, DH Valentine, SM Walters, DA Webb (eds.): Flora Europaea . 2nd, revised edition. Volume 1: Psilotaceae to Platanaceae . Cambridge University Press, Cambridge / New York / Melbourne 1993, ISBN 0-521-41007-X , pp. 53–64 (English, limited preview in Google Book Search).
  • HM Schiechtl: Pastures in Practice - The pastures of Central Europe, their use and their purpose. Patzer, Berlin / Hanover 1992, ISBN 3-87617-082-6 .
  • TA Volk et al .: Developing a Willow Biomass Crop Enterprise for Bioenergy and Bioproducts in the United States . ( online ).
  • M. Zander, K.-J. Endtmann, B. Schröter: Investigations of selected Salix clans of the NE German lowlands. Taxonomy, sociology, distribution, isoenzyme analyzes. In: Writings on Genetic Resources. Volume 1, 1994, pp. 168-183 ( PDF file; 588 kB ).

Web links

Commons : Weiden ( Salix )  - Album with pictures, videos and audio files
Wiktionary: Willow  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. MC Alliende, JL Harper: Demographic Studies of a dioecious tree. I. Colonization, Sex and Age Structure of a Population of Salix cinerea. In: Journal of Ecology . Volume 77, No. 4, 1989, pp. 1029-1047, JSTOR 2260821 , ( PDF file ( Memento of December 26, 2011 in the Internet Archive )).
  2. ^ Jörg Mildenberger: Anton Trutmann's 'Pharmacopoeia', Part II: Dictionary. Würzburg 1997, Volume V, p. 2285.
  3. Almut Bick: The Stone Age. Theiss WissenKompakt, Stuttgart 2006, ISBN 3-8062-1996-6 .
  4. D. Grosser, W. Teetz: Weide . In: Arbeitsgemeinschaft Holz eV (Ed.): Local timber (loose-leaf collection) . No. 15 . Information service wood, wood sales fund - sales promotion fund of the German forest and wood industry, 1998, ISSN  0446-2114 .
  5. a b Salix at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed December 24, 2016.
  6. a b c d e f g h i j k l m n o p q r s t u v w x Salix in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved December 24, 2016.
  7. a b c d e f g h Pertti Johannes Uotila, 2011: Salicaceae . Datasheet Salix In: Euro + Med Plantbase - the information resource for Euro-Mediterranean plant diversity.
  8. FloraWeb
  9. a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba bb bc bd be bf bg bh bi bj bk bl bm bn bo bp bq br bs bt bu bv bw bx by bz Cheng-fu Fang, Shi-dong Zhao, Alexei K. Skvortsov: Salix. In: Wu Zheng-yi, Peter H. Raven (Ed.): Flora of China . Volume 4: Cycadaceae through Fagaceae . Science Press / Missouri Botanical Garden Press, Beijing / St. Louis 1999, ISBN 0-915279-70-3 , pp. 162-274 (English). , PDF file , HTML version at efloras.org.
  10. Alekseĭ Konstantinovich Skvortsov, Alexei G. Zinovjev: Willows of Russia and adjacent countries. Taxonomical and geographical revision (= University of Joensuu Faculty of Mathematics and Natural Sciences report series Biology. 39; translated by Irina N. Kadis). University of Joensuu, Joensuu, Finland 1999 (Russian original: 1968), ISBN 951-708-766-7 , p. 212, (PDF file) .
  11. George W. Argus: Salix. In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico . Volume 7: Magnoliophyta: Salicaceae to Brassicaceae . Oxford University Press, New York / Oxford a. a. 2010, ISBN 978-0-19-531822-7 , pp. 23–162 (English, limited preview in Google Book Search). , HTML version at efloras.org.
  12. Hieronymus Bock . Kreüter Bůch. Wendel Rihel, Strasbourg 1546, part III, chapter 60 (sheet 53r): Weiden / Felbinger. … To the fourth / the rope willows with the ash-colored bark and leaves / so annually for the first time in the spring the grows bring ketzlin / and for a number of those the palm trees / for the thunderstorm / are consecrated. ... ( digitized versionhttp: //vorlage_digitalisat.test/1%3D~GB%3D~IA%3D~MDZ%3D%0A11200232_00867~SZ%3D~ double-sided%3D~LT%3D~PUR%3D )