White berry mistletoe

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White berry mistletoe
White berry mistletoe (Viscum album)

White berry mistletoe ( Viscum album )

Systematics
Eudicotyledons
Nuclear eudicotyledons
Order : Sandalwoods (Santalales)
Family : Sandalwood family (Santalaceae)
Genre : Mistletoe ( viscum )
Type : White berry mistletoe
Scientific name
Viscum album
L.

The white berry mistletoe ( Viscum album ), usually called mistletoe , with its three subspecies, namely the hardwood, fir and pine races, is a plant species in the sandalwood family (Santalaceae). It is often placed together with some other genera such as Arceuthobium in a separate family Viscaceae , which then includes around 400 species. It is one of the few parasitic vascular plant species in Europe that parasitizes directly on the shoot axes of the host plants.

description

illustration
Male flower
Leaves, flowers and berry of fir mistletoe ( Viscum album subsp. Abietis )
Sliced ​​fruit of pine mistletoe ( Viscum album subsp. Austriacum )
Pine mistletoe seeds ( Viscum album subsp. Austriacum )
White berry mistletoe embryos
Dried seed core of white berry mistletoe with two germinated embryos
Attachment of mistletoe to a branch of a pine
Section through a mistletoe infestation on pine , the defense efforts of the tree through overgrowth and resin formation can be clearly seen
Haustorium , illustration
Hardwood mistletoe ( Viscum album subsp. Album ), extensive infestation on a poplar in the Rheinauewald
Fir mistletoe ( Viscum album subsp. Abietis )
Pine mistletoe ( Viscum album subsp. Austriacum )

Appearance and leaf

The white berry mistletoe grows as a lush green - in the case of the rarer male specimens: yellowish-green - evergreen shrub parasitizing on other woody plants. This semi-parasite sits on the branches of trees and removes water and the mineral salts dissolved in it from their wooden part. Over the years, mistletoes often grow into spherical bushes that can be up to 1 meter in diameter. The mistletoe's shoot axes, which are often evenly forked, are divided by furrows at the nodes (nodes) and break off there easily. There are three to five indistinct leaf veins . These run in parallel and are not networked.

At the ends of the stem axles sit opposite the sessile leaves , which can be perennial. The somewhat thick, almost leathery, simple leaf blade is 2.5 to 7 centimeters long and 0.5 to 3.5 centimeters wide and elliptical to obovate-lanceolate or obovate with a blunt upper end. Both sides of the leaf appear similar (equifacial) and have clearly recessed stomata. Because of their "evergreen", or at least evergreen, leaves our mistletoes form over the years a wood in which - similar to boxwood , holly and ivy - annual rings are only indistinctly recognizable. In contrast to the three evergreen trees mentioned, the leaves of the white berry mistletoe do not stay longer than two years and therefore only stay on the plant in the outer zone.

blossom

The flowering time of the white berry mistletoe extends from mid-January to the beginning of April when the weather is favorable in Central Europe. The white berry mistletoe is dioeciously separated ( diocesan ). Three to five flowers are clustered together in the uppermost leaf axils. The two bracts are about 2 millimeters long, concave and ciliate with a blunt upper end.

The inconspicuous, unisexual flowers are sessile. The three or four free, thick bracts are triangular and obsolete with a length of about 1 millimeter in the female flowers. The four stamens in the flowers of the (much rarer) male (staminate) plants have no stamens. The back overgrown with here about twice as long bloom cladding dust bag open with many pores; they have a distinct, fruity scent. The under constant ovary is at a length of about 2 millimeters obovate. The seated scar is conical with a length of about 1 millimeter.

Fruit and seeds

It takes around nine months from the flowering in February to the ripe berries in the Advent season. The white, somewhat translucent, lonely berries are spherical with a diameter of about 1 centimeter. The 5 to 6 millimeter long seeds are surrounded by a white, tough, slimy, sticky pulp (pulp). In the case of our hardwood and south-western European red berries mistletoe, up to three or, very rarely, four green embryos form in individual seeds .

Chromosome number

The number of chromosomes is 2n = 20.

ecology

The white berry mistletoe is a shrub-like semi-parasite on the branches and occasionally on the trunks of various trees. From their wooden part, the so-called xylem , it extracts water and the nutrient salts dissolved in it. Because of the strong transpiration required for this, the leaves of the mistletoe feel cool, which is interpreted as evaporation cold. The plants can grow into spherical bushes with a maximum diameter of 1 meter and can live up to about 70 years. The growth is very slow; the growth is one branch per year. Branches 50 centimeters long are said to be around 30 years old. When they first bloom, mistletoes are six to seven years old. The green bark of the shoots does not form a layer of cork and can therefore photosynthesize for years .

The pollen grains are connected to one another by delicate, elastic, sticky viscine threads, so they cannot be carried by the wind . The pollen transfer (pollination) does not take place "by the wind" or by bees, but mainly by flies, as Joseph Gottlieb Kölreuter had already determined, which, however, was not believed for a long time.

The sticky pulp that surrounds the seeds allows them to spread through birds. The seeds of most types of mistletoe are spread by birds (digestive spread, endozoochory ). With us, for the white berry mistletoe, the usual propagator birds are the mistletoe , the blackcap and the occasional winter guest waxwing . Only they eat the glutinous fruits of mistletoe. However, you cannot digest the viscous slime-coated inner part with the seeds. That is why the seeds with their sticky mucous membrane are excreted by mistletoe and waxwings after a very short intestinal passage. If the excretions of these birds - whether sitting or flying over them - get caught on the branches of trees that are not "mistletoe-proof", then the green embryos in the seed kernels have the chance to germinate and establish themselves there successfully. Black warblers attach the seed kernels with their inner mucous membrane, before they swallow the outer part of the berry, directly with their bills on a nearby branch. This can also be a sprout of the mistletoe itself. They can germinate successfully there too, because mistletoe itself is by no means mistletoe-proof. In both cases, germination is always particularly successful as soon as rain and sun provide favorable conditions.

During germination, the hypocotyl first stretches . It curves downwards away from the light (negative phototaxis ). As soon as its tip reaches the base (if possible, the host's bark), it forms an adhesive disc there. From its center, the seedling first drives a penetration wedge , then a suction process ( haustorium ) through the bark of the host branch. The young mistletoe then slowly spreads in the sap path between the bark and wood in the form of green bark suction cords . In the course of time, the central haustorium develops into a primary root that grows further and further into the host tissue as the thickness of the supporting branch grows. In the following year, so-called sinker roots grow out of the primary roots, which penetrate into the host's tissue and are also able to develop new sinkers and root shoots themselves. Only after the sinker roots have reached the host's pathways does the mistletoe develop further. After many years, the mistletoe is so richly branched that it can form spherical bushes up to a meter in diameter or loosely hanging shapes. For the host plant, the parasitism of mistletoe can mean that the branch on which the mistletoe lives or the whole tree dies. Harvest losses often occur on orchards when the host plant no longer has sufficient water and nutrients available to produce enough fruit.

The green embryos are already photosynthetically active in the translucent berries. After implantation in living bark, an early stage of development can barely survive for a few years as long as the haustoria cells cannot reach the pathways of the host plant. The reason why the young mistletoe sometimes remains in this cryptic state has not yet been explored.

Another special feature of mistletoe is that, as a photosynthetically active semi-parasite, it actually only has to withdraw water and mineral salts from its host, which is why it still amazes many researchers today that it nonetheless taps into the pathways for the host's organic substances (the phloem ). Whether it also removes nutrients from the host is still being discussed critically at the moment.

distribution

The distribution area of ​​the white berry mistletoe is the mild winter regions of southern Scandinavia as well as central and southern Europe. There it thrives on deciduous trees such as apple trees, linden trees, maples, birches, poplars and willows, hornbeams, hawthorns and especially lush and broad-leaved on robinia. Red beeches ( Fagus ), oaks and z. B. the plane trees are mistletoe-proof . Around 1900 mistletoe was introduced into the United States as a neophyte or consciously naturalized by the gardener Luther Burbank and has spread to many different types of wood north of San Francisco .

In addition to Viscum album , the oak mistletoe ( Loranthus europaeus ), which belongs to a different genus and family, occurs in Central Europe . In contrast to the white berry mistletoe, this is only summer green and has branches that are brown to black-gray from the 2nd year on. The oak mistletoe makes yellow berries.

Systematics

The scientific name of the white berry mistletoe, Viscum album L. , was first published in 1753 by Carl von Linné in Species Plantarum .

Within the species Viscum album , a distinction is made between several subspecies that are linked to different host tree species:

  • Hardwood mistletoe ( Viscum album L. . Subsp album ) - on poplars and willows, to pome fruit plants on apple trees, rowan , hawthorn and the großstrauchigen Canadian Juneberry on stone fruit plants in rock cherry and black cherry , on birch, hazel, locust and gold rain, Linden, maple trees, lilac and privet, American red and swamp oak, Balkan and Appalachian (= yellow) horse chestnuts , North American black walnut , American ash, American alder, American elm ( Ulmus americana ), hornbeam and others; on pear trees, sweet cherry and plum trees only extremely rarely, but not at all, for example, on red beech, walnut, plane trees, paulownia, god's trees or magnolias. The number of chromosomes in this subspecies is 2n = 20.
  • Fir mistletoe ( Viscum album . Subsp abietis . (Wiesb) Janchen , Syn .: Viscum abietis (Wiesb) Fritsch.) - on individual Fir Tree, at least white and Greek fir ( Abies cephalonica ) and extremely rare even on a spruce and on a deciduous tree species. In the Allgäu Alps it barely exceeds an altitude of 1000 meters.
  • Pine mistletoe , pine mistletoe ( Viscum album subsp. Austriacum (Wiesb.) Vollm. , Syn .: Viscum laxum Boiss. & Reut.) - on pine, very rarely on spruce and larch. Occurrence in southern and eastern Germany: from Iffezheim on both sides of the Rhine northwards, in and around the Nuremberg Reichswald, Brandenburg; Austria (often to scattered in the colline to montane altitude level of the federal states of Vienna , Burgenland , Carinthia (uncertain), Lower Austria , Upper Austria , Styria , Tyrol and Vorarlberg ), South Tyrol and Japan. The chromosome number of this subspecies is 2n = 20. It occurs in societies of the Erico-Pinion association.
  • Cretan mistletoe ( Viscum album subsp. Creticum N.Böhling et al.) , Another subspecies described in 2002, which only occurs as an endemic on Crete and there parasitizes on the Calabrian pine ( Pinus brutia ).

The Korean or Japanese mistletoe, which used to be a subspecies ( Viscum album subsp. Coloratum ), is now viewed as a separate species ( Viscum coloratum ). Some authors have the Asian subspecies Viscum album subsp. meridianum (Danser) DGLong .

Toxicity

According to the assessment of the poison control center at the University of Bonn's clinic, mistletoe is slightly toxic, in all parts of the plant except for the berries. Coniferous mistletoe bushes broken down after storms and male specimens of hardwood mistletoe can be fed and are welcome green fodder for livestock and game in winter. The female bushes of the hardwood breed should, however, be avoided as food because of their unusually sticky berries inside, as they can get stuck in the throat, which is very uncomfortable. Children are urgently warned about these berries.

use

General use

The fruits, especially oak mistletoe (which, however, belongs to a different family) were previously used to make bird glue because of the sticky mesocarp . In some European countries, this cruel way of catching birds is still a popular “sport” despite a ban in the EU.

Mistletoes are very suitable for wild gardens, because they are easy to plant, because it is sufficient to attach the fresh, still sticky seeds to a young bark of a suitable, mistletoe-proof host tree.

Use as a medicinal plant

The dried, young branches with leaves, flowers and fruits were used as medicinal drugs. Ingredients are lectins (glycoproteins), viscotoxins (toxic polypeptides ), water-soluble polysaccharides , biogenic amines , flavonoids , lignans , cyclitols such Viscumitol and phenol carboxylic acids .

Traditionally, mistletoe tea or corresponding ready-made preparations with mistletoe extracts to support the circulatory system with a tendency to hypertension and for arteriosclerosis prophylaxis were taken for use. So far, however, there has not been sufficient proof of effectiveness in these indications.

Despite many years of use and research, it has not been proven that mistletoe preparations can inhibit tumor growth or even cure cancer patients. The successes are interpreted in terms of unspecific stimulation therapy, in no way as a direct cytotoxic effect of the preparations. In individual studies, slight to moderate effects on the disease process could be observed through the injection therapy with corresponding mistletoe preparations. However, there was a very small number of participants in these studies and no untreated control group, so the validity of these studies remains unclear.

mythology

Mistletoe was already known in ancient mythology and was used by the Gallic priests, the druids , as a remedy and for cultic acts. Celtic priests especially considered the rare specimens that grew on oak trees to be sacred. It was not only considered a miracle plant against diseases, but was also venerated as a sanctuary, as a sign of everlasting life and was a symbol of fertility for the Celts and Germanic peoples. The Teutons believed that the gods scattered mistletoe seeds in the trees, so they were a gift from heaven.

Some old customs are still maintained today. In some countries, such as Switzerland , mistletoe is a symbol of fertility. In England there is a ritual that a mistletoe is hung over the door at Christmas time and the young lady who is under this mistletoe can be kissed on the spot. In France, mistletoe is also hung over the door on New Year's and everyone kisses the relatives and friends underneath. There is also a saying: Au gui, l'an neuf , which means "New Year comes with the mistletoe".

In Germanic mythology , the Asen god Balder was killed with a mistletoe.

Similar species

Compare also:

  • Red berry mistletoe ( Viscum cruciatum ), a dioecious relative of the white berry mistletoe, with disjoint occurrences in southern Spain ( Andalusia ), northwestern Africa and in Palestine , which parasitizes mainly on olive trees such as the olive tree and the lilac . Their fruits also usually have multi-embryonic seed kernels.
  • Oak mistletoe , belt flower ( Loranthus europaeus )
  • Dwarf mistletoe ( Viscum minimum ), a full parasite / endophyte inside some cactus-like milkweed species in South Africa , with red berries.
  • Dwarf mistletoe in the true sense ( Arceuthobium ) are the leafless, inconspicuous, but sometimes very damaging species of the Viscaceae genus. These only parasitize on conifers. They are distributed all over the northern hemisphere. They throw their seeds up to twenty meters with extreme water pressure, a propagation mechanism that is extremely rare in the plant kingdom ( Canadian Journal of Botany. Volume 82, p. 1566). They occur particularly rich in species in North America. In Europe, only the very inconspicuous juniper mistletoe ( Arceuthobium oxycedri ) occurs from this genus, which comprises a little over 30 species , for example in southern France.

literature

  • Priscilla Abdulla: Flora of West Pakistan 35: Loranthaceae . Stewart Herbarium, Gordon College (inter alia), Rawalpindi 1973, Viscum album ( online ).
  • Willem Frans Daems , Gundolf Keil : The mistletoe tract of the Vienna Codex 3811. In: Sudhoffs archive. Volume 49, 1965, ISSN  0931-9425 , pp. 90-93.
  • Ruprecht Düll , Herfried Kutzelnigg : Pocket dictionary of plants in Germany. A botanical-ecological excursion companion to the most important species . 6th, completely revised edition. Quelle & Meyer, Wiebelsheim 2005, ISBN 3-494-01397-7 .
  • Peter Luther, Hans Becker: The mistletoe: botany, lectins, medical application. Berlin, Heidelberg etc. 1987.
  • Thomas Schauer: The FSVO plant guide for on the go. blv, Munich 2005, ISBN 3-405-16908-9 .
  • Hans Christian Weber: parasites. Plants that live on others. Belser, Stuttgart 1978, ISBN 3-7630-1834-4 .
  • Hans Christian Weber: Parasitism of flowering plants. Scientific Book Society, Darmstadt 1993, ISBN 3-534-10529-X .
  • Ingrid Schönfelder, Peter Schönfelder: The new book of medicinal plants. Franckh-Kosmos, Stuttgart 2011, ISBN 978-3-440-12932-6 .
  • Lutz Roth, Max Daunderer, Kurt Kormann: Poison Plants - Plant Poisons. Occurrence, effect, therapy, allergic and phototoxic reactions. With a special section about poisonous animals. 6th, revised edition, special edition. Nikol, Hamburg 2012, ISBN 978-3-86820-009-6 .
  • Ruprecht Düll , Herfried Kutzelnigg : Pocket dictionary of plants in Germany and neighboring countries. The most common Central European species in portrait . 7th, corrected and enlarged edition. Quelle & Meyer, Wiebelsheim 2011, ISBN 978-3-494-01424-1 .

Individual evidence

  1. ↑ a b c Misteln to Natur-Lexikon.com (a private website without naming its own sources) , accessed on May 7, 2015
  2. ↑ a b c Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas. 8th edition. Verlag Eugen Ulmer, Stuttgart 2001, ISBN 3-8001-3131-5 , pages 324-325.
  3. ↑ Botanical Garden: Unter dem Mistelzweig , Uni Erlangen 12/2011, accessed on May 7, 2015
  4. ^ A b c d e W. Oßwald: Wood diseases in words and pictures: Viscum album L. - Mistletoe ( Memento from June 10, 2007 in the Internet Archive ).
  5. ^ A b Manfred A. Fischer, Karl Oswald, Wolfgang Adler: Excursion flora for Austria, Liechtenstein and South Tyrol . 3rd, improved edition. Province of Upper Austria, Biology Center of the Upper Austrian State Museums, Linz 2008, ISBN 978-3-85474-187-9 , p. 388 .
  6. ↑ The Euro + Med PlantBase - the information resource for Euro-Mediterranean plant diversity , accessed on October 26, 2014
  7. ↑ Carl von Linné: Species Plantarum. Volume 2, Lars Salvius, Stockholm 1753, p. 1023, digitizedhttp: //vorlage_digitalisat.test/1%3Dhttp%3A%2F%2Fwww.biodiversitylibrary.org%2Fopenurl%3Fpid%3Dtitle%3A669%26volume%3D2%26issue%3D%26spage%3D1023%26date%3D1753~GB%3D~ IA% 3D ~ MDZ% 3D% 0A ~ SZ% 3D ~ double-sided% 3D ~ LT% 3D ~ PUR% 3D
  8. ↑ Erhard Dörr, Wolfgang Lippert : Flora of the Allgäu and its surroundings. Volume 1, IHW, Eching 2001, ISBN 3-930167-50-6 , p. 436.
  9. ↑ Viscum laxum at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
  10. ↑ Niels Böhling, Werner Greuter, Thomas Raus, Britt Snogerup, Sven Snogerup, Doris Zuber: Notes on the Cretan mistletoe, Viscum album subsp. creticum subsp. nova (Loranthaceae / Viscaceae). In: Israel Journal of Plant Sciences. Volume 50, Supplement, 2002, pp. S77-S84, DOI: 10.1560 / RRJ4-HU15-8BFM-WAUK .
  11. ^ A b Huaxing Qiu, Michael G. Gilbert: Viscum. In: Wu Zhengyi, Peter H. Raven, Deyuan Hong (Eds.): Flora of China . Volume 5: Ulmaceae through Basellaceae . Science Press / Missouri Botanical Garden Press, Beijing / St. Louis 2003, ISBN 1-930723-27-X , pp. 242–245 (English, online - PDF file ).
  12. ^ Center for Pediatrics. Information center against poisoning .
  13. ↑ M. Mabed, L. El-Helw, S. Shamaa: Phase II study of viscum fraxini-2 in patients with advanced hepatocellular carcinoma. In: British Journal of Cancer . Volume 90, Number 1, January 2004, ISSN  0007-0920 , pp. 65-69, doi : 10.1038 / sj.bjc.6601463 , PMID 14710208 , PMC 2395314 (free full text).
  14. ↑ F. Schad, J. Atxner, D. Buchwald, A. Happe, S. Popp, M. Kröz, H. Matthes: intratumorally Mistletoe (Viscum album L) Therapy in Patients With unresectable pancreatic carcinoma: A Retrospective Analysis. In: Integrative cancer therapies. [Electronic publication before printing] Number 4, December 2013, ISSN  1552-695X , doi : 10.1177 / 1534735413513637 , PMID 24363283 .
  15. ↑ W. Tröger, D. Galun, M. Reif, A. Schumann, N. Stanković: Viscum album [L.] extract therapy in patients with locally advanced or metastatic pancreatic cancer: A randomized clinical trial on overall survival . In: European Journal of Cancer . tape 49 , no. December 18 , 2013, p. 3788–3797 , doi : 10.1016 / j.ejca.2013.06.043 ( elsevier.com [accessed September 25, 2019]).
  16. ↑ Bernhard Maier: Druids: Mistletoe and Human Sacrifice , November 28, 2010, accessed on May 7, 2015.

Web links

Wiktionary: Mistletoe  - explanations of meanings, word origins, synonyms, translations
Commons : White berry mistletoe ( Viscum album )  - album with pictures, videos and audio files