Black fruit two-tooth
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Black-fruited two-toothed tooth ( Bidens frondosus ) |
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The Schwarzfrüchtige Bidens ( Bidens frondosus , Syn. : Bidens melanocarpus ) is a plant from the family of the daisy family (Asteraceae).
description
Vegetative characteristics
The black fruited two-toothed tooth is an annual herbaceous plant that reaches a height of between 30 and 120 cm, but in exceptional cases it can be up to 3 m high in the reeds. This species usually grows heavily branched from the bottom with branches pointing diagonally upwards. The stem is often purple in color. The opposite leaves are long stalked and usually three-part (up to five-part) pinnate. The lanceolate leaflets are clearly serrate and seated on the leaf spindle with a narrowed, often asymmetrical base. In contrast to the three-part two-tooth and the radial two-tooth , the leaves are completely separated into partial leaflets.
Generative characteristics
The flowering period extends from August to September. The cups are surrounded by five to eight unequal bracts , which are usually narrowly lanceolate in shape. The bracts of the cups, on the other hand, are broadly oval and sometimes a little reddish in color at the tip. The flower heads, which are 5 to 10 mm in diameter, contain only yellow tubular flowers . On the base of the inflorescence between the tubular flowers there are blackish, dry chaff leaves . Ray florets are absent.
The flat, blackish to blackish-brown achenes are also bumpy on the surface. On top of the achenes sit two awn-shaped teeth, which are usually set with backward-pointing spines.
The number of chromosomes is 2n = 48.
Systematics
The variety Bidens frondosus var. Frondosus
Biden frondosus var. Frondosus ( habit )
Bidens frondosus var. Frondosus ( herbarium evidence )
Biden frondosus var. Frondosus ( inflorescence with fruit)
fruit
The variety Bidens frondosus var. Anomalus
The variety Bidens frondosa var. Anomala Porter ex Fernald is rarer than the mostly occurring nominate form Bidens frondosa var. Frondosa . In the case of Bidens frondosa var. Anomala , the awns of the fruits are provided with upward-pointing spines, in contrast to the variety Bidens frondosa var. Frondosa .
Bidens frondosus var. Anomalus ( herbarium evidence )
Bidens frondosus var. Anomalus (Habitus)
Bidens frondosus var. Anomalus ( inflorescence )
Bidens frondosus var. Anomalus (fruits)
Occurrence
General distribution
The homeland of Bidens frondosus is Canada and the United States. In the meantime it has spread as a neophyte in Europe, Asia, Morocco and New Zealand . Its distribution area extends from Portugal and Spain, France and the Netherlands to Italy, Bosnia, Austria, Germany, the Czech Republic, Hungary and Poland. It shows a sub-Mediterranean-subatlantic spreading tendency. In Austria one finds this species scattered to moderately often along the big rivers, in Switzerland it is naturalized in southern Ticino.
Distribution in Germany
The black fruited bizarre occurs scattered in the northern area along the large rivers. In some cases it is already quite common there. It is increasingly penetrating the central and southern areas, especially along the navigable rivers. It is only rarely found on the Danube.
Location requirements
The black fruited two-toothed tooth grows on banks, rivers, ditches, ponds, lakes, roadsides, etc. It prefers moist to wet, at times flooded, nutrient- and nitrogen-rich, muddy soils. It is also rarely found in dry ruderal areas. In Central Europe it is a character species of the order Bidentetalia tripartitae.
literature
- Henning Haeupler , Thomas Muer: picture atlas of the fern and flowering plants of Germany (= the fern and flowering plants of Germany. Volume 2). Published by the Federal Agency for Nature Conservation. Ulmer, Stuttgart 2000, ISBN 3-8001-3364-4 .
- Wolfgang Adler, Karl Oswald, Raimund Fischer: Excursion flora of Austria. Ed .: Manfred A. Fischer . Ulmer, Stuttgart / Vienna 1994, ISBN 3-8001-3461-6 .
- August Binz , Christian Heitz: School and excursion flora for Switzerland , Schwabe & Co. AG, Basel, 1986, ISBN 3-7965-0832-4
- Erich Oberdorfer : Plant-sociological excursion flora , Ulmer Verlag, Stuttgart, 1990, ISBN 3-8001-3454-3
- Christian August Friedrich Garcke : Illustrierte Flora , 1972, Paul Parey publishing house, Berlin and Hamburg. ISBN 3-489-68034-0
- Gerhard Wagenitz : Bidens . In Gustav Hegi : Illustrated Flora of Central Europe . Volume VI, Part 3, 2nd edition, Paul Parey, Berlin, Hamburg, 1964–1979. Pp. 219-237. ISBN 3-489-84020-8
- Henning Haeupler, Peter Schönfelder , Franz Schuhwerk (Hrsg.): Atlas of the fern and flowering plants of the Federal Republic of Germany . Verlag Eugen Ulmer, Stuttgart 1988. ISBN 3-8001-3434-9
Individual evidence
- ↑ a b 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 , pp. 929 .
- ^ Bidens frondosa in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved May 1, 2016.
Web links
- Black fruit two-tooth. In: FloraWeb.de.
- Black fruit two-tooth . In: BiolFlor, the database of biological-ecological characteristics of the flora of Germany.
- Profile and distribution map for Bavaria . In: Botanical Information Hub of Bavaria .
- Bidens frondosa L. In: Info Flora , the national data and information center for Swiss flora . Retrieved May 1, 2016.
- Thomas Meyer: Zweizahn data sheet with identification key and photos at Flora-de: Flora von Deutschland (old name of the website: Flowers in Swabia )