Polygonum aviculare

Knotweed ( Polygonum aviculare )

The knotweed ( Polygonum aviculare ) is a plant of the family buckwheat family ( Polygonaceae ). It is a collective species with several small ways.

Description

The knotweed is an annual herbaceous plant. The roots in 25 to 80 centimeters deep. The usually low -lying, rare upright stems are 5 to 60 centimeters long. The leaves are elliptic - lanceolate and grass to blue- green. The slashed Ochrea is shorter than the internodes, silvery- translucent, against the base often brownish and has a maximum of six unbranched veins.

The flowering period extends usually from May to October (April to November). The flowers are leafy branches to the tip. The flowers are single or two to six in small, axillary groups. The perianth of five bloom cladding is usually greenish with white, pink or reddish margin. The three pens are very short. The flowers are odorless, do not produce nectar and are therefore rarely visited by insects. The knotweed is mainly autogamous.

The matt or shiny, grooved or smooth nut fruits are usually 2 to 3 millimeters long and usually much longer than the perianth.

Dissemination

Werner Roth painter is the dissemination than in the meridional and circumpolar boreal zone and in the austral zone. Erich Oberdorfer they are as a Mediterranean - Eurasian- nordic, in the temperate zones worldwide today. The knotweed is very common in Central Europe. It grows from the plains to the mountains in the Alps to an altitude of 1200 meters, in the Black Forest to 1360 meters.

The knotweed is a pioneer plant and grows mostly on trails, debris, ditches, gravel sites, crossing points, fields. It grows on dry to moderately dry, wet, rich or raw stone, sand and clay soils. He is a nitrogen pointer. Phytosociological the knotweed is typical of the Association Polygonion avicularis and the classes Polygono - Poetea ( Annuelle kick grass) Secalietea ( cereal weeds companies) and Chenopodietea ( weed and ruderal ).

The knotweed is a cultural companion since the Neolithic period.

Ecology

The knotweed is summer annual plant. Vegetative propagation is done by rooting runners. The knotweed is very resistant occurs. Its young leaves at night cause of sleep movements by providing up straight and put together.

The flowers are inconspicuous and have no nectar. Flowers Ecologically they form a transition between " Bellflower " and " disk flowers ". The self-pollination is predominant. The flowering time is already in the 5th week after germination.

The propagation takes place by means Epizoochorie. The fruits propagate as Regenschwemmlinge and propagation occurs as water oats. Further processing is done spread by birds, for example, by sparrows and random dispersal by ungulates. Fruit ripening starts from July. The seeds are long-lived heat to germinate. The seeds remain viable for up to 250 years.

Use

The knotweed is an old bird food plant.

Young stems and leaves have long been used as a vegetable.

Pharmacology

As drug (pharmaceuticals ) collected during the flowering season aboveground plant parts are used ( Polygoni avicularis herba ).

Active substances are: silica ( partly water-soluble), tannins ( gallotannins and Catechingerbstoffe ) flavonoids, especially avicularin, phenolic acids and mucilage.

Today, the medicinal plant is only occasionally used as a tea for catarrh of the upper respiratory tract due to their (albeit small ) ejection promoting effect and is included in blends or as an extract in the corresponding finished products. The attributable to the tannin content of astringent properties are still used for rinsing and gargling with ease inflammation in the mouth and throat, as well as external applications for skin impurities and treating wounds.

System

Erich Oberdorfer different aviculare agg within the Polygonum. for Germany following small ways:

• Polygonum calcatum
• Polygonum microspermum
• Polygonum aequale
• Polygonum monspeliense
• Polygonum heterophyllum Polygonum heterophyllum subsp. virgatum

Fischer distinguishes between the following subspecies for Austria:

• Polygonum aviculare subsp. depressum ( = P. arenastrum )
• Polygonum aviculare subsp. rurivagum
• Polygonum aviculare subsp. neglectum
• Polygonum aviculare subsp. aviculare