Cuscuta europaea

Nettle Silk ( Cuscuta europaea)

Called Cnidarians silk ( Cuscuta europaea), also European silk or silk - hop, is a flowering plant in the family of wind plants ( Convolvulaceae ). There is a full parasites.

Description

The Nettle Silk is an annual herbaceous plant. The nominate Common Nettle Silk ( Cuscuta europaea L. subsp. Europaea) has a thread-like, 20 to 100 cm long, intertwining stems from initially greenish or reddish- yellow color, and later he is about to run red. Leaves and roots are missing. Chlorophyll is present only in residues.

The flowering period extends from June to September. In the axils of minute bracts sit in little head shaped inflorescences, which have a diameter of 10 to 15 mm. The reddish to whitish- yellow or pure white flowers are three to fünfzählig (usually fourfold ). The Kronblattschuppen are small, delicate or absent, the corolla tube is therefore open. Each flower contains two to four pens, which terminate in filiform scars.

Are formed with four hard-shelled seed capsule fruits. Fruit ripening is from August to September.

Ecology

The Nettle silk grows in moist and nutrient-rich Staudengesellschaften locations, especially in river valleys. As host plants for the full parasites serve nettle, hops and other herbaceous plants.

The Nettle Silk is a Therophyt, this full parasites is therefore an annual. He is a left- Winder. The thread-like germ leafless seedling moves away the fact that it continues to grow at the top and at the rear end dies, the materials move forward. Upon contact with a host plant he winds around it and forms Saugfortsätze ( haustoria ) that penetrate under resolution of the cell walls of the host to the sieve and vessel parts and there remove water and dissolved assimilates. However, can also refer to sugar from the plant host, without entering into the phloem. In case of excessive exploitation can bring the host plant also to die. Recently, it was demonstrated that the targeted movement of Cuscuta seedlings is controlled in the direction of their potential host plant by the formation of the host plant volatile ingredients which means " smell" the parasites to their host.

Between the parasite and the host plant occupied a gene replacement has been variously stated.

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

Ecologically flowers is " bluebells with sticky pollen " The nectar is covered. As a visitor you can wasps, especially grave wasps, watch ( wasps flower). The flowers remain partially closed ( ie kleistogam ), their lifespan is about ten days.

The fruit capsules are surrounded by the permanent perianth and are thus specific weight. This allows for a wind spread as a balloon pilot and a swimming propagation. For this is done randomly spread by grazing animals and probably spread by floating seeds. The seeds are dark to germinate and remain viable in the soil 5 to 10 years.

The silk of the genus Cuscuta serve as a forage crop for small weevils of the genus Smicronyx. The beetle larvae develop into stalk thickening (bile ), whose formation is caused by the oviposition of the female beetles. In Europe, up to five different Smicronyx - types can be found at the Nettle silk.

Subspecies

When Nettle Silk ( Cuscuta europaea), there are three subspecies:

• The Common Nettle Silk ( Cuscuta europaea L. subsp. Europaea)
• The Wicken silk ( Cuscuta europaea subsp. Viciae ). It grows in vetches and lentil fields and other Leguminosenansaaten.
• The hedges silk ( Cuscuta europaea subsp. Nefrens ). You " Leeches" inter alia on Prunus, buck thorn ( Lycium ) and nettles (Urtica ).