Fine jet
| Fine jet | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Fine jet ( Erigeron annuus ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Erigeron annuus | ||||||||||||
| ( L. ) Desf. |
The fine blasting ( Erigeron annuus ), also White Horseweed or Einjähriges Horseweed called, is a plant of the genus erigeron ( Erigeron ) within the family of Compositae (Asteraceae).
description
Vegetative characteristics
The fine jet grows as an annual or biennial herbaceous plant and reaches heights of 50 to 100 centimeters. The stem is independently upright. The leaves are simple with a serrate to almost smooth edge.
Generative characteristics
The flowering period extends from June to October. In an umbrella-like overall inflorescence , numerous cup-shaped partial inflorescences are arranged, the terminal inflorescence is dominated by the lateral ones. The green bracts are almost equally long and not hairy.
The white to pale purple ray flowers (ray flowers) are 4 to 10 millimeters long and 0.6 to 1 millimeters wide. The yellow tubular flowers are 2 to 2.8 millimeters long. The pappus of the tubular flowers is very short and single-rowed.
The basic chromosome number is x = 9; were chromosome numbers of 2n = 27, 36 or determined 54th
ecology
With its roots penetrating up to 1 meter into the ground, the fine jet is considered a pioneer plant . It reproduces largely asexually, i.e. H. Seeds are formed even without fertilization ( apomixis ).
Occurrence
The annual fine jet originally occurs in North America. Since the 18th century it has been naturalized as a neophyte in Europe, Turkey, the Caucasus, India, China, Korea, Réunion, New Zealand, Nicaragua and Panama. In Austria the kind is absent-minded to common in all federal states. In Germany, the spread decreases roughly from south to north. It can be found frequently in the Black Forest, but only rarely in some northern German areas. The fine beam is also widespread in Switzerland, where it was included in the black list of invasive neophytes due to its potential for spreading and damage in the areas of biodiversity , health and economy .
The fine jet usually thrives in alluvial forests , damp meadows and ruderal meadows .
The annual fine ray often occurs in Central Europe together with Solidago gigantea in societies of the class Artemisietea.
Systematics
The first publication took place in 1753 under the name (Basionym) Aster annuus by Carl von Linné . The new combination Erigeron annuus (L.) Desf. was published in 1804 by René Louiche Desfontaines . Other synonyms for Erigeron annuus (L.) Desf. are: Phalacroloma annuum (L.) Dumort. , Stenactis annua (L.) Less.
There are several subspecies in Central Europe, the distribution of which has in part been insufficiently researched:
- Multi-leaf fine ray ( Erigeron annuus (L.) Desf. Subsp. Annuus ): The number of chromosomes is 2n = 27 or 54.
- Nordic fine beam ( Erigeron annuus subsp. Septentrionalis (Fernald & Wiegand) Wagenitz , Syn .: Erigeron ramosus var. Septentrionalis Fernald & Wiegand ): The number of chromosomes is 2n = 27.
- Branched fine blasting or harrow Hairy fine beam ( Erigeron annuus subsp. Strigosus (Willdenow) Wagenitz )
literature
- Manfred A. Fischer, Wolfgang Adler, Karl Oswald: Excursion flora for Austria, Liechtenstein and South Tyrol . 2nd, improved and enlarged edition. State of Upper Austria, Biology Center of the Upper Austrian State Museums, Linz 2005, ISBN 3-85474-140-5 .
Individual evidence
- ↑ a b c 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. 915 .
- ↑ a b Erigeron in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved February 23, 2018.
- ^ Federal Office for the Environment FOEN: Invasive Alien Species . ( admin.ch [accessed on August 6, 2019]).
- ↑ S. Buholzer, M. Nobis, N. Schoenenberger, S. Rometsch: List of the alien invasive plants of Switzerland . Ed .: Infoflora. ( infoflora.ch [accessed on August 6, 2019]).
Web links
- Erigeron annuus (L.) Pers., Fine jet fleabane. In: FloraWeb.de.
- Erigeron annuus subsp. annuus (L.) Pers., fine ray fleabane (subspecies). In: FloraWeb.de.
- Erigeron annuus subsp. septentrionalis (Fernald & Wiegand) Wagenitz, northern fine ray fleabane. In: FloraWeb.de.
- Fine jet . 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 .
- Erigeron annuus (L.) Desf. s. st. In: Info Flora , the national data and information center for Swiss flora . Retrieved April 18, 2016.
- Erigeron annuus subsp. septentrionalis (Fernald & Wiegand) Wagenitz In: Info Flora , the national data and information center for Swiss flora . Retrieved April 18, 2016.
- Erigeron annuus subsp. strigosus (Willd.) Wagenitz In: Info Flora , the national data and information center for Swiss flora . Retrieved April 18, 2016.
- Thomas Meyer: Fleabane data sheet with identification key and photos at Flora-de: Flora von Deutschland (old name of the website: Flowers in Swabia ).
- Characteristics. (engl.)
- Guy L. Nesom: Erigeron. Erigeron annuus Pers., P. 344 - the same text online as the printed work , In: Flora of North America Editorial Committee (Hrsg.): Flora of North America North of Mexico. Volume 20: Magnoliophyta: Asteridae, part 7: Asteraceae, part 2 (Astereae, Senecioneae) , Oxford University Press, New York and Oxford. 2006, ISBN 0-19-530564-7 .
- Erigeron annuus at Plants For A Future
- Erigeron annuus in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.