Nettle silk

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Nettle silk
Nettle silk (Cuscuta europaea)

Nettle silk ( Cuscuta europaea )

Systematics
Euasterids I
Order : Nightshade (Solanales)
Family : Bindweed family (Convolvulaceae)
Tribe : Cuscuteae
Genre : Silk ( cuscuta )
Type : Nettle silk
Scientific name
Cuscuta europaea
L.

The Cuscuta europaea ( Cuscuta europaea ), and European silk or hop-Silk called, is a flowering plant in the family of wind plants (Convolvulaceae). It is a complete parasite .

description

Illustration of nettle silk on nettle
Clusters of flowers
Inside of the crown with gullet scale
Flower with four corolla lobes and two linear stigmas
Seeds
Nettle silk on nettles
Nettle silk on compass lettuce
Nettle silk

Vegetative characteristics

The nettle silk is an annual herbaceous plant . The nominate form Ordinary nettle silk ( Cuscuta europaea subsp. Europaea ) has a thread-like, 20 to 100 centimeter long, twisting stem of initially greenish or reddish-yellow color, later it is overflowing with red. There are no leaves and roots . Chlorophyll is only present in residues.

Generative characteristics

The flowering period extends from June to September. In the axils of tiny bracts sit in head-shaped inflorescences that have a diameter of 10 to 15 millimeters. The reddish to whitish-yellow or pure white flowers are three to five-fold (mostly four-fold). The petal scales are small, delicate or absent, the corolla tube is therefore open. Each flower contains two to four styles that end in thread-like stigmas .

There are fruit capsules each with four hard-shelled seeds formed. Fruit ripening is from August to September.

The number of chromosomes is 2n = 14.

ecology

The nettle silk is a therophyte , so this parasite is annual. He's a left winder . The thread-like, cotyledon-free seedling moves by the fact that it continues to grow at the tip and dies at the rear end, with the building materials moving forward. When it comes into contact with a host plant, it winds around it and forms suction processes ( haustoria ) which, by dissolving the host's cell walls, penetrate to the sieve and vessel parts, where they withdraw water and the dissolved assimilates . However, the plant can also obtain sugar from the host without penetrating the sieve part. If over-exploited, it can also cause the host plant to die. It was recently demonstrated that the targeted movement of the Cuscuta seedlings in the direction of their potential host plant is controlled by volatile substances released by the host plant, which means that the parasites “smell” their host. The host plants for the parasite are nettles , hops , bindweed , common mugwort , potatoes and other herbaceous plants .

A gene exchange has also been found on various occasions between the parasites and the occupied host plant.

Depending on the host, there is a long- day or short-day plant .

In terms of flower ecology, it is “bluebells with sticky pollen”. The nectar is covered. As a visitor you can observe wasps , especially digger wasps ( wasp flower ). The flowers remain partially closed ( i.e. cleistogamous ) and their lifespan is about ten days.

The capsule fruits are surrounded by the permanent flower envelope and are therefore specifically light. This enables the wind to spread as a balloon pilot and a swimming spread. In addition, it is spread randomly by grazing animals and probably also by swimming seeds. The seeds are dark germiners and remain viable in the soil for five to ten years.

The silk species of the genus Cuscuta are used as fodder for small weevils of the genus Smicronyx . The beetle larvae develop in thickened stems ( galls ), the formation of which is caused by the oviposition of the female beetles. In Europe, up to five different types of Smicronyx can be found on nettle silk .

Occurrence

The distribution area of Cuscuta europaea extends over the temperate zones of Eurasia to northern India . The nettle silk grows in perennial communities in moist and nutrient-rich locations, especially in river valleys. It likes to grow in moist, nutrient-rich locations and is a river valley plant . In Central Europe it is a type of character of the Cuscuto-Convolvuletum.

In the Allgäu Alps , it rises on the Stuhlwand on the Grünten in Bavaria at altitudes of up to 1500 meters.

Systematics

The first publication of Cuscuta europaea was in 1753 by Carl von Linné .

In the case of nettle silk ( Cuscuta europaea ), some authors in Europe distinguish three varieties (some authors also use them as subspecies):

  • Ordinary Cuscuta europaea ( Cuscuta europaea L. var. Europaea )
  • Vetch silk ( Cuscuta europaea var. Viciae Engelm. , Syn .: Cuscuta europaea subsp. Viciae (Engelm.) Gan. ): It grows in vetch and lentil fields and other legume seeds .
  • Hedge silk ( Cuscuta europaea var. Nefrens Fr. , Syn .: Cuscuta europaea subsp. Nefrens (Fr.) O.Schwarz ): It "parasites" and a. on prunus , buckthorns ( Lycium ) and nettles ( Urtica ).

Some authors group the three European varieties into Cuscuta europaea var. Europaea .

Some authors have the following varieties:

  • Cuscuta europaea var. Conocarpa Engelm.
  • Cuscuta europaea L. var. Europaea
  • Cuscuta europaea var. Indica Engelm. (Syn .: Cuscuta indica (Engelm.) Petrov ex Butkov ): It occurs in Turkey and from the Himalayas to northern India .
  • Cuscuta europaea var. Nepalensis Yunck. : It occurs in Nepal.

Common names

The other German-language trivial names exist or existed for nettle silk : Filtzekruit ( Middle Low German - Rhenish ), Falsches Frauenhaar, Unser Fruen Seiden ( Middle High German ), Klebe, Kleeseide, Kleise, Leithaar, Nesseldoder (Middle High German), Nesseltottern (Middle High German), Nettle tendrils ( East Prussia ), nettle silk ( Silesia ), Nesselside (Middle Low German-Rhenish), Rangen, Side (Middle Low German-Rhenish), Teufelszwirn, Tuhnsied ( Mecklenburg ) and Great Vogelseide.

literature

  • Hans Christian Weber: Schmarotzer: Plants that live on others. Belser, Stuttgart 1978, ISBN 3-7630-1834-4 .
  • 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 Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . With the collaboration of Angelika Schwabe and Theo Müller. 8th, heavily revised and expanded edition. Eugen Ulmer, Stuttgart (Hohenheim) 2001, ISBN 3-8001-3131-5 .
  2. ↑ Identification key of the Smicronyx weevils
  3. ↑ Erhard Dörr, Wolfgang Lippert : Flora of the Allgäu and its surroundings. Volume 2. IHW-Verlag, Eching near Munich 2004. ISBN 3-930167-61-1 , p. 360.
  4. ↑ a b c d Rafaël Govaerts (Ed.): Cuscuta europaea. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved July 31, 2015.
  5. ^ Georg August Pritzel , Carl Jessen : The German folk names of plants. New contribution to the German linguistic treasure. Philipp Cohen, Hannover 1882, p. 123 ( online ).

Web links

Commons : Nettle Silk ( Cuscuta europaea )  - Album with pictures, videos and audio files