Overgrown-leaved two-tooth
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Overgrown two-toothed tooth ( Bidens connata ) |
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| Mill. ex Willd. |
The fused-leaf bizarre ( Bidens connata ) is a species of the sunflower family (Asteraceae) and is quite rare in Central Europe. It blooms in August and September.
description
The fused-leaf bizarre grows as an annual herbaceous plant and reaches a height of 15 to 150 centimeters. The stem is usually bare and purple. The leaves are lanceolate to rhombic-lanceolate in shape and undivided. They are roughly serrated with up to five teeth on each side and narrowed into a winged stem at the base of the spread. The tip of the leaf is long and imperforate. With strong plants it happens that the lower leaves are divided pinnately.
The flower heads are very long and about 15 millimeters wide. The number of outer foliage-like bracts is usually four to six; these are much longer than the inner ones. The ray-florets are missing, the tubular-florets are brownish-yellow in color, but often overflowed with red. The achenes are three to four-sided and have a rhombic cross-section. The outer fruits usually have four awns and are clearly narrowed.
The number of chromosomes is 2n = 24, 48 or 72.
distribution
General distribution
The home of Bidens connata is northeastern North America. In the meantime it has also spread to a certain extent in Europe as a neophyte . It shows a subatlantic spreading tendency. This species is absent in Austria, while in Switzerland it is naturalized in the Rhine Valley.
Distribution in Germany
The fused-leaf bizarre occurs in Germany scattered or rarely along the large rivers. However, it is often inconsistent. Observations of Bidens connatus from Germany were first described in 1865.
Location requirements
The overgrown two-toothed tooth grows in bank communities, on rivers, ditches and ponds. It prefers wet, nutrient-rich, open, muddy bottoms. In Central Europe it is a character species of the Bidention tripartitae association.
Systematics
According to John L. Strother and Ronald R. Weedon in the Flora of North America, this species should better be associated with Bidens tripartitus .
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, ISBN 3-489-68034-0
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 .
- ↑ John L. Strother, Ronald R. Weedon: Bidens . In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico , Volume 21, New York and Oxford: Bidens connata - online.
- ^ Bidens in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved March 13, 2018.
Web links
- Overgrown-leaved two-tooth. In: FloraWeb.de.
- Overgrown-leaved 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 connata Willd. 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 )