Amaranthus retroflexus

Back Curved amaranth

The Recurved amaranth ( Amaranthus retroflexus ), also known as redroot pigweed, is a flowering plant in the family Amaranthaceae ( Amaranthaceae ). He is in Central Europe, a common heat- loving " weed " in maize and sugar beet fields, house and vegetable gardens and vineyards.

Description

The Recurved Amaranth grows reaches as annual herbaceous plant, the plant height of 15 cm to 100 cm (mostly 30 to 40 cm). The upright and usually upright projecting branched stem is fluffy shaggy - haired to short and sometimes especially crowded in the lower part with reddish stripes. The color of the aerial parts of plants may be pale green, grass green or bluish green. The upper part of a meter deep, thick root is often reddish or pink.

The change-constant and long -stalked leaves are sometimes up to 10 cm long, elliptic- ligulate, rhombic to oval with a length of about 5. From the midrib of the leaves go from more or less parallel lateral nerves.

The flowering period extends from July to September. The dense, translucent eared total inflorescence consists of dichasialen flower balls together and terminally dense, racemose inflorescence part to aged men. In the axils sit further, smaller inflorescences. The inflorescences are upright or tilted at the top. The flowers are in the axils of bracts longer. This approximately 5 mm long bracts of the flowers are stiff and bespitzt. This increases the inflorescences feel to rough to spiky. The inconspicuous flowers are fünfzählig. The perianth is like straw - dry. The Perigonzipfel the female flowers widen after flowering front and spatulate front and emarginate in shape or truncate, sometimes with a small spike tip.

The fruit capsule opens up with a dish-shaped lid. The fruits are thin -shelled, irregular aufreißende nuts, which hold a shiny black seeds.

Ecology

The Back Curved fox tail is a Therophyt, sommerannuell woody with age, even through the winter permanent aboveground plant parts. At night cause the leaves from sleep movements and stand upright. The plant follows, like all species of the genus Amaranthus, the C4 pathway of photosynthesis, and it is thus capable in warm regions to higher production. Amaranthus is of the type, in which carbon dioxide is bound as aspartate. The species is a deep-rooting and rooted to a, possibly even up to two meters deep.

There is Windblütigkeit. The solidified fruit stems and branches allow skidding movements in the wind: There is a wind - and animal spreader before. The small, only 0.4 mg of heavy seeds are also spread as a balloon pilot and as granules flyer. One plant can produce up to 100,000 seeds. The seeds are durable and heat to germinate. Also editing spread by seed eaters happens. Besides swimming and raindrops propagation takes place. The main propagation takes place in Central Europe, however, with garden and field soil by humans. Fruit ripening is from August to October

Occurrence

The Recurved amaranth comes from the temperate and warmer regions of eastern and central North America ( northeastern Mexico to Canada).

He has since been deported on all continents to Europe in the 18th century. The Back Curved fox tail is wild in Central Europe since the early 19th century and a neophyte. The first evidence in Germany dates back to 1815.

The Recurved amaranth growing as " weeds " in vineyards, in fields, in gardens or on roadsides and is a characteristic species of nitrogen-rich root crop - weed societies. It also occurs on the banks of rivers, as the seeds can easily spread through the water. The plant does not tolerate frost and survived as seeds.

Another name for the Curved Back amaranth is also the name Stirr occupied for Transylvania.

Swell

• Werner Rothmaler: Exkursionsflora the territories of the GDR and the FRG. Volume 2: vascular plants, 14th edition. Volk und Wissen, Berlin 1988, ISBN 3-06-012539-2
• Otto Schmeil, Jost hinge plates, Werner Rauh: Flora of Germany and its neighboring areas. 84th edition. Quelle & Meyer, Heidelberg 1968.
• R. Duell, H. Kutzelnigg: Pocket Dictionary of Plants in Germany. 6th edition.
• NeoFlora ( Federal Agency for Nature Conservation )
• Amaranthus retroflexus in the Flora of North America.
• R. Duell / H. Kutzelnigg: Pocket Dictionary of Plants in Germany and neighboring countries, 7th Edition, Quelle & Meyer Verlag, 2011, ISBN 978-3-494-01424-1