Hedge knotweed

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Hedge knotweed
Fallopia dumetorum.jpg

Hedge knotweed ( Fallopia dumetorum )

Systematics
Nuclear eudicotyledons
Order : Clove-like (Caryophyllales)
Family : Knotweed family (Polygonaceae)
Subfamily : Polygonoideae
Genre : Winged knotweed ( fallopia )
Type : Hedge knotweed
Scientific name
Fallopia dumetorum
( L. ) Holub

The hedge knotweed or hedge knotweed ( Fallopia dumetorum (L.) Holub ; Syn .: Polygonum dumetorum L. ) is a species of the knotweed genus ( Fallopia ) in the knotweed family (Polygonaceae). It occurs in the temperate latitudes of Eurasia and grows on hedges and bushes, as well as forest fringes and clearings.

description

illustration
Unripe winged fruits
Ripe winged fruits
The perigone surrounding the fruit is glandless and the outer tepals are broadly winged and descend on the fruit stalk. This is divided into or below the middle.
The fruits are smooth and shiny.

Fallopia dumetorum is a one-year , herbaceous plant . The usually 60 to 150 centimeters, more rarely up to 3 meters long stalk grows creeping and climbing and right-winding; in contrast to the very similar knotweed ( Fallopia convolvulus ), it is round and smooth. All parts of the plant are bare. The root is spindle-shaped. The leaves are divided into petiole and leaf blade. There is a nectar pit at the base of the petiole. The leaf blade is elongated and pointed and at the base of the blade it is arrow-shaped to heart-shaped with two lateral, triangular or rounded lobes.

The flowering period is between July and September. The loose, lateral or terminal and pseudo-eared inflorescences contain two to five flowers. The 5 to 8 millimeter long flower stalks are divided below the middle. The pericarp is 7 to 9 millimeters long at the time of fruiting. The green-whitish, brown or reddish, 1 to 3 millimeter wide bracts are glandless and glabrous. The three outer ones are membranous, the wings are rounded at the top and run down a little on the stem at their base. The - in contrast to Fallopia convolvulus - smooth, shiny and black nut is 2.5 to 3 millimeters long and three-sided with rounded edges and falls off with the upper part of the inflorescence.

The number of chromosomes is 2n = 20.

ecology

As a spreading climber , the hedgerow knotweed often forms thicket-like vegetation. Remarkably, it is one of the few plant species that can twist both right and left, this is even possible with the same specimen.

The homogeneous flowers are only spread out when the sun is shining. Initially only insect pollination takes place , but later spontaneous self-pollination is possible.

Because of the winged, permanent tepals, the fruit spreads as a rotary wing.

Occurrence

distribution

The hedge knotweed occurs in the temperate latitudes of Eurasia . In Europe, the distribution extends northwards to southern Sweden, in Asia eastwards to northeast China and the Amur region . In Central Europe , the hedgehog knotweed is common or widespread in the north German lowlands . In Central Germany it occurs in lowlands and in the hill country, in the mountain country it is rare. In southern Germany it occurs mainly in river valleys with a warm climate (e.g. on the Upper Rhine and Neckar) and is very rare in other large areas (e.g. south of the Danube). In some places the occurrence extends into the foothills of the Alps. The hedgerow knotweed is sometimes found in the Alps at altitudes of up to 1250 meters ( Canton Valais ).

The hedge knotweed was introduced to North America and is found in the eastern half of the United States and southeastern Canada . Since Fallopia dumetorum is often confused with Fallopia scandens, information on distribution is quite unreliable and the size of the species area is probably mostly overestimated.

Locations and socialization

In Central Europe , the hedge knotweed occurs scattered to often on hedges and bushes, as well as forest fringes and clearings. It grows in mostly fresh, nutrient-rich locations with lime-poor to lime-rich sandy and loamy soils. The species can often be found in bushes and riparian forests. There it forms, partly with other climbing plants, impenetrable thickets (dampening veil societies).

The hedgerow knotweed is often associated with either burdock bedstraw and pigeon goiter or with hops , stinging nettle , dewberry , vetch , meadow pea , bindweed and the red fruited bryan. Sometimes it forms the only vegetation on moist, grassless soil in which the common evening primrose can also be found. In Central Europe it is a character type of the societies of the Alliarion association, but also occurs in other societies of the Galio-Urticenea subclass.

Taxonomy

This species was by Carl Linnaeus in 1762 in Species Plantarum , Editio Secunda, 1, p 522 under the name Polygonum dumetorum first published . Josef Holub placed it in 1971 in Folia Geobotanica et Phytotaxonomica , 6 (1), p. 176 in the genus Fallopia . Other synonyms for Fallopia dumetorum (L.) Holub are: Bilderdykia scandens (L.) Greene var. Dumetorum (L.) Dum. , Polygonum scandens var. Dumetorum (L.) Gleason , Reynoutria scandens var. Dumetorum (L.) Shinners , Tiniaria dumetorum (L.) Opiz .

swell

  • Rudolf Schubert, Walter Vent (Ed.): Excursion flora from Germany. Founded by Werner Rothmaler . 8th edition. Volume 4: Critical Volume, People and Knowledge, Berlin 1990. ISBN 3-06-012526-0 .
  • Margot Spohn, Marianne Golte-Bechtle: What is blooming there? The encyclopedia: over 1000 flowering plants from Central Europe. Kosmos, Stuttgart 2005, ISBN 3-440-10326-9 .
  • Gerhard Wagenitz (Hrsg.): Illustrated flora of Central Europe. Pteridophyta, Spermatophyta . Founded by Gustav Hegi. 3rd, revised and expanded edition. Volume III. Part 1: Angiospermae: Dicotyledones 1 (Juglandaceae - Polygonaceae) . Paul Parey, Berlin / Hamburg 1981, ISBN 3-489-59020-1 , p. 430 f . (Reprint of the 2nd edition from 1957/1958 with addendum).
  • 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 .
  • Oskar Sebald, Siegmund Seybold, Georg Philippi (Hrsg.): The fern and flowering plants of Baden-Württemberg . tape 1 : General Part, Special Part (Pteridophyta, Spermatophyta): Lycopodiaceae to Plumbaginaceae . Eugen Ulmer, Stuttgart (Hohenheim) 1990, ISBN 3-8001-3309-1 .

Individual evidence

  1. ↑ a b c d e Gerhard Wagenitz (Ed.): Illustrated flora of Central Europe. Pteridophyta, Spermatophyta . Founded by Gustav Hegi. 3rd, revised and expanded edition. Volume III. Part 1: Angiospermae: Dicotyledones 1 (Juglandaceae - Polygonaceae) . Paul Parey, Berlin / Hamburg 1981, ISBN 3-489-59020-1 , p. 430 f . (Reprint of the 2nd edition from 1957/1958 with addendum).
  2. ↑ a b c Hedge knotweed. In: FloraWeb.de.
  3. ↑ a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . 8th edition. Verlag Eugen Ulmer, Stuttgart 2001, ISBN 3-8001-3131-5 . Page 338.
  4. ^ Burkhard Quinger: Polygonaceae . In: Oskar Sebald , Siegmund Seybold , Georg Philippi (eds.): The fern and flowering plants of Baden-Württemberg . 2nd Edition. tape 1 . Verlag Eugen Ulmer, Stuttgart 1993, ISBN 3-8001-3322-9 , p. 514-576, here pp. 541-543 .
  5. ↑ Craig C. Freeman, Harold R. Hinds: Fallopia. : Fallopia dumetorum - the same text online as the printed work , In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico , Volume 5 - Magnoliophyta: Caryophyllidae, part 2 , Oxford University Press, New York and Oxford, 2005. ISBN 0-19-522211-3
  6. ↑ First publication scanned at biodiversitylibrary.org .
  7. ↑ Fallopia dumetorum at Tropicos.org. Missouri Botanical Garden, St. Louis, Retrieved September 7, 2011.

Web links

Commons : Hedge Knotweed ( Fallopia dumetorum )  - Collection of images, videos and audio files