Jacob's ragwort

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Jacob's ragwort
Jacob's ragwort (Senecio jacobaea)

Jacob's ragwort ( Senecio jacobaea )

Systematics
Order : Astern-like (Asterales)
Family : Daisy family (Asteraceae)
Subfamily : Asteroideae
Tribe : Senecioneae
Genre : Jacobaea
Type : Jacob's ragwort
Scientific name
Jacobaea vulgaris
Garden.

The Ragwort ( Jacobaea vulgaris , Syn. Senecio jacobaea ), and Jakob-Greiskraut and Ragwort and ragwort called, is a species of the genus Senecio within the family of Compositae (Asteraceae).

The plant is originally native to Europe and West Asia and is now also found in America and Oceania. All of its parts are poisonous.

The species name refers to the flowering date around Jacobi (July 25th) - but actually the flowering time begins at the beginning of June with sparse inflorescences. The inflorescences are actually only fully developed in midsummer .

description

Basal leaf rosette in the first year of life
Baskets typical of daisy plants with ray and tubular flowers
illustration
Tubular flowers in detail
illustration

Vegetative characteristics

Senecio jacobaea is a mostly biennial , sometimes longer perennial herbaceous plant and reaches heights of 30 to 100 centimeters. In the first year, a basal leaf rosette is formed from leaves about 20 centimeters long . An upright stem (stem) with inflorescences, often covered in dark red , does not develop until the second year. In the lyre-shaped pinnate leaves , the irregular and blunt-toothed sections are widened towards the end; at their base they have auricles.

Generative characteristics

In the upper part of the plant there are numerous yellow, cup-shaped partial inflorescences in a widely branched, umbrella-like overall inflorescence. The flower heads have a diameter of about 15 to 25 millimeters. The flower heads have an envelope of 13 bracts and adjacent (or only one or two protruding) outer bracts. The tips of the bracts are mostly black in color. The yellow ray-florets are usually well developed, but can also be absent; their number is usually between 12 and 15 per flower head.

The achenes are crowned by a pappus . The number of chromosomes is 2n = 40. After blooming, about 70 seeds develop per flower head, some of which are equipped with fly and adhesive hairs.

Ram as a flower visitor on Jacob's groundwort
Jacob's wort bear caterpillars ( Tyria jacobaeae ) on the tongue flowerless subspecies Dune Jacob's ragwort ( Senecio jacobaea subsp. Dunensis )
Dried ragwort

ecology

The pappus , which serves to spread the wind ( anemochory ) , falls off slightly from the achenes.

In summer, you can see caterpillars with striking yellow and black stripes on Jacob's ragwort. These are caterpillars of the Jacob's cabbage bear ( Tyria jacobaeae ), a type of butterfly that specializes in ragweed, especially Jacob's ragwort. The caterpillars become inedible for predators due to the poison they have ingested.

Jacob's ragwort is attacked by the rust fungus Coleosporium senecionis with aecidia and basidiosori .

Following the example of combating the poisonous herb in North America and New Zealand, researchers in Schleswig-Holstein will be using flea beetles in addition to caterpillars. These eat the roots of the Jacob's herb.

However, the native Jacob's ragwort is also a natural part of the cultural landscape. It is used as a forage plant for many insect species, some of which have specialized in the species that bloom in July, as the food supply is rather scarce at this time.

Occurrence

The original distribution area of Jacob's ragwort are the plains to middle mountain ranges of the temperate climatic zones of Europe and Western Asia. In Central Europe it is not a neophyte , but a native species. It occurs in Argentina, New Zealand, Australia, Canada and in the USA as an invasive neophyte.

Jacob's ragwort is quite widespread on the edges of fields, on meadows , fallow fields , grasslands and in other grass and herbaceous areas . His demands on the floor are not particularly great. It thrives best on moderately fresh or alternately fresh, more or less nutrient and base-rich, humus clay and sand soils in a humid climate . It is considered a character species of the association Cynosurion, but it also occurs in associations of the associations Arrhenatherion, Mesobromion, Koelerio-Phleion or Dauco-Melilotion.

Since the seeds of the ragwort adhere well to agricultural machinery, other means of transport, for example, as well as clothing, fur and feathers, in addition to the spread of wind, it quickly establishes itself on neighboring areas.

In the Allgäu Alps , it rises above the Ifenhütte on the Hohen Ifen in Vorarlberg to an altitude of 1710 meters.

Systematics

The subdivision of the large genus Senecio by Augustin-Pyrame de Candolle in 1838 lasted essentially into the 21st century. Only with the advent of new techniques, which succeeded in examining the relationship of the species by comparing homologous DNA sequences ( phylogenomics ), was it possible to break down the old large genus into natural units. It soon became apparent that the traditional Jacobaeae section within the genus Senecio , whose type species is Senecio jacobaea , belongs to a species group that is only relatively distantly related to the actual genus Senecio . From these and later studies that confirmed the result, taxonomists drew the conclusion to (again) promote the previous section to the new genus Jacobaea . In order to avoid the tautonym " Jacobaea jacobaea ", which is forbidden according to the rules , the old synonymous species name Jacobaea vulgaris was reactivated for Jacob's ragwort . The new species structure of the tribe Senecioneae is generally accepted technically, but has not yet been reproduced in most of the applied works, so that in most of the writings the common groundwort is still listed under the old scientific name Senecio jacobaea . The genus Jacobaea is mainly delimited according to genetic characteristics, convincing morphological autapomorphies could not be given so far.

The name Jacobaea vulgaris was published by Gottfried Gaertner . Synonyms for Jacobaea vulgaris Gaertn. are: Senecio jacobaea L. , Senecio flosculosus Jord. , Senecio foliosus DC. , Senecio jacobaeoides Willk. , Senecio nemorosus Jord. , Senecio jacobaea subsp. nudus (Weston) Soják , Senecio praealtus subsp. foliosus (DC.) Cout. Weston , Senecio jacobaea var. Nudus .

There are about three subspecies:

  • Dune Jacob's ragwort ( Jacobaea vulgaris subsp. Dunensis (Dumort.) Pelser & Meijden , Syn .: Senecio jacobaea subsp. Dunensis (Dumort.) Kadereit & PDSell , Senecio dunensis Dumort. ): It is characterized by lower growth, lack of ray florets and cobweb-like, woolly hairs and occurs on the coasts of Great Britain, Ireland, Belgium, the Netherlands, Germany, Denmark, Norway, Sweden and Poland.
  • Jacobaea vulgaris subsp. gotlandica (Neuman) B.Nord. (Syn .: Senecio jacobaea subsp. Gotlandicus (Neuman) Sterner ): It occurs in Sweden, Italy, Austria, Montenegro, Greece and Russia.
  • Common Jacob's ragwort ( Jacobaea vulgaris Gaertn. Subsp. Vulgaris , Syn .: Senecio jacobaea L. subsp. Jacobaea )

Ingredients and toxicity

This type of plant is not welcomed by farmers and horse owners because all of its parts are poisonous due to the liver-damaging pyrrolizidine alkaloids it contains, even if they come into contact with the skin. The content in the flowers is up to twice as high as in the herb. In detail, acetyl, E - and Z -Erucifolin containing 21-Hydroxyintegerrimin, Integerrimin, Jacobin, Jacolin, Jaconin, Jacozin, retrorsine, Ridellin, senecionine, seneciphylline, Senecivernin, Spartioidin and Usaramin. In contrast to many other poisons, the alkaloids remain effective when preserved in hay or silage and are also ingested in this way by grazing animals, which otherwise actually avoid the herbs, which otherwise taste bitter when fresh. Even small doses damage the liver permanently, so that a gradual poisoning is possible for years. In horses in particular , but also in cattle , the herb can lead to serious illnesses and ultimately death. The deadly dose for horses is 40 to 80 grams of fresh plants per kilogram of body weight, and 140 grams for cattle. Sheep and goats are less sensitive, but if larger amounts are consumed (two to four kilograms per kilogram of body weight), deaths should also occur in these cases. It appears that rabbits and various rodents (such as guinea pigs and gerbils ) are resistant to orally ingested ragwort venom. However, intravenous administration of the poison resulted in the death of rabbits, which suggests that it is inactivated or not absorbed in the animals' gastrointestinal tract . Rabbits like the roots of the ragwort and the decline in the rabbit population is believed to be one reason for the increase in the abundance of the ragwort. Because of its toxicity, the herb is no longer used as a medicinal plant.

It is possible that pyrrolizidine alkaloids are introduced into the human food cycle via plant food components. The transfer of pyrrolizidine alkaloids into nectar and with this into honey has been proven. Investigations showed a comparatively low level of contamination in German honeys; this is more critical with honeys from overseas. The Federal Institute for Risk Assessment demands zero tolerance for pyrrolizidines due to the extreme toxicity; To this day, however, there are neither regulations regarding maximum quantities nor regular controls for food. Control programs for teas and herbal teas were started by the Federal Institute for Risk Assessment, for honey by the Freiburg Chemical and Veterinary Investigation Office .

Two chemotypes can be distinguished within the species : a Jacobin chemotype common in northwestern Europe and an erucifolin chemotype common in southeastern Europe.

Combat

Employees of the Hochsauerlandkreis Biological Station fight ragwort by pulling it out in the Westfalenhang nature reserve

In North Rhine-Westphalia, from 2008 onwards there was an increased spread on set-aside areas, extensively used pastures, especially horse pastures, extensive grassland areas, roadsides and embankments. Jacob's ragwort was found there on pastures with insufficient pasture care and neglected aftermath. It is therefore particularly common on horse pastures, since grazing horses hardly eat the plants, unlike cattle or sheep. On horse pastures you will also find overgrazed areas and places with bare ground, where the ragwort finds optimal germination conditions. In order to prevent the plant from forming seeds, it is advisable to mow the affected areas at the latest at the beginning of flowering. The ragwort can be pushed back by pruning twice before flowering. Jacob's ragwort, especially individual plants, can also be controlled mechanically, primarily by tearing or cutting out.

The North Rhine-Westphalia Chamber of Agriculture is of the opinion that chemical control with herbicide can hardly be avoided in the event of severe infestation , provided that there is no two mowing. As a preventive measure, a dense sward should be ensured without any defects so that the seeds cannot germinate. According to the Chamber of Agriculture, reseeding with grass seeds should be carried out in the event of defects. The Federal Institute for Risk Assessment also gives this recommendation for cattle pastures. The Schleswig-Holstein Nature Conservation Union (NABU), on the other hand, warns against scaremongering and points out the important ecological role of the plant. For example, four species of flea beetles are dependent on Jacob's groundwort. NABU sees the increased occurrence of Jacob's ragwort as an indication of overstocking in paddocks and points out that the plant has little chance of development on conventionally tended cattle pastures. An important predator of the Jacob's ragwort is a butterfly, the blood bear . Observations in the Heidkoppelmoor nature reserve have shown that dense stocks of St. James's ragwort collapse on their own within two years.

In order to prevent further spread, the Bavarian State Office for the Environment recommends that you use and dispose of the clippings so that no parts of the plant or seeds get into the landscape. When transporting material, attention must therefore be paid to the packaging of the cut material. Disposal on a dung stick, garden compost or in conventional green waste collection points should be avoided, as this encourages further spread.

reception

The Greek doctor Pedanios Dioscurides from the 1st century AD recommended ragwort as a medicinal plant . The same did the British botanist John Gerard (1545–1612) and the doctor Nicholas Culpeper (1616–1654). Culpeper was also an astrologer, which is why he took the view that the plant was under the influence of Lady Venus and therefore has a cleansing and digestive effect.

The English natural poet John Clare (1793–1864) gave a positive impression of the plant in his poem published in 1831:

“Ragwort thou humble flower with tattered leaves
I love to see thee come and litter gold…
Thy waste of shining blossoms richly shields
The sun tanned sward in splendid hues that burn
So bright and glaring that the very light
Of the rich sunshine doth to paleness turn
And seems but very shadows in thy sight. "

"Jakobskraut you humble flower with tattered leaves
I love to see you come and see gold scattered ...
Your waste of shiny blossoms abundantly shields the
sun-tanned sward in splendid hues that burn
So bright and glaring that the light
From the rich sunshine it turns pale
And it just seems to be very shadowy in your eyes. "

- John Clare

Under its Manx Gaelic name, Cushag, ragwort is the Isle of Man's national flower . Legend has it that King Gottfried IV († 1095) chose the Cushag flower for his coat of arms, as each of its "twelve" petals represented one of the islands of his kingdom of Mann : the Isle of Man, Isle of Arran , Isle of Bute , Islay , Jura , Isle of Mull , Iona , Eigg , Rùm , Skye , Raasay and the Outer Hebrides . However, the flower head of the ragwort usually has thirteen "petals" (actually they are ray flowers ).

The Manx poet Josephine Kermode (1852–1937), on the other hand, wrote the following poem about the Cushag and thus addresses the problematic nature of the plant:

“Now, the Cushag, we know, must never grow,
Where the farmer's work is done.
But along the rills, in the heart of the hills,
The Cushag may shine like the sun.
Where the golden flowers,
have fairy powers,
To gladden our hearts with their grace.
And in Vannin Veg Veen,
In the valleys green,
The Cushags have still a place. "

“Well, the Cushag, we know, must never grow
where the farmer's work is done.
But along the trenches, in the heart of the hills,
The Cushag may shine like the sun.
Where the gold blooms, have
fairy power,
To please our hearts with their grace.
And in Vannin Veg Veen,
In the valleys green,
The Cushags still have their place. "

- Josephine Kermode :

Here is Vannin Veg Veen as Manx Gaelic name for the dear little Isle of Man .

literature

  • Henning Haeupler, Thomas Muer: picture atlas of the fern and flowering plants of Germany . Ed .: Federal Agency for Nature Conservation (=  The fern and flowering plants of Germany . Volume 2 ). Eugen Ulmer, Stuttgart (Hohenheim) 2000, ISBN 3-8001-3364-4 .
  • 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 .
  • Eckehart J. Jäger (Ed.): Rothmaler, Exkursionsflora von Deutschland. 20th edition

Web links

Commons : Jacob's Ragwort ( Jacobaea vulgaris )  - Album with pictures, videos and audio files

Individual evidence

  1. ↑ a b c d Werner Greuter : Compositae (pro parte majore). Jacobaea vulgaris Gaertn. In: Werner Greuter, Eckhard von Raab-Straube (ed.): Compositae. at Euro + Med Plantbase - the information resource for Euro-Mediterranean plant diversity .
  2. ↑ 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.  955 .
  3. ↑ a b c d Radkowitach, A., Zehm, A., Gehring, K .: Management of problem species: Jacob's ragwort - Senecio jacobaea. Bavarian State Office for the Environment, 2018, accessed on July 16, 2019 .
  4. ^ Dellbrücker Heide Retrieved June 11, 2012
  5. ↑ Peter Zwetko: The rust mushrooms Austria. Supplement and host-parasite directory to the 2nd edition of the Catalogus Florae Austriae, III. Part, Book 1, Uredinales. , 2000 (PDF; 1.8 MB).
  6. ↑ Fight against the Ragwort A caterpillar as a poisonous plant killer? , Deutschlandfunk Kultur on July 21, 2017
  7. ↑ Erhard Dörr, Wolfgang Lippert : Flora of the Allgäu and its surroundings. Volume 2, IHW, Eching 2004, ISBN 3-930167-61-1 , p. 624.
  8. ^ Pieter B. Pelser, Barbara Gravendeel, Ruud van der Meijden (2002): Tackling speciose genera: species composition and phylogenetic position of Senecio sect. Jacobaea (Asteraceae) based on plastid and nrDNA sequences. American Journal of Botany 89 (6): 929-939.
  9. ↑ Pieter B. Pelser, Bertil Nordenstam, Joachim W. Kadereit, Linda E. Watson (2007): An ITS phylogeny of tribe Senecioneae (Asteraceae) and a new delimitation of Senecio L. Taxon 56 (4): 1077-1104.
  10. ↑ PB Pelser, J.-F. Veldkamp R. van der Meijden (2006): New combinations in Jacobaea Mill. (Asteraceae - Senecioneae). Compositae Newsletter 44: 1-11.
  11. ↑ a b c Rudolf Hänsel et al. (Ed.): Hager's handbook of pharmaceutical practice. Drugs P – Z , Springer, Berlin 1994, p. 669 f .: [1]
  12. ↑ Leaflet Julius Kühn Institute : Jacob's ragwort (Senecio jacobaea). Detection and control options in grassland , 2nd edition Nov. 2010 (PDF; 903 kB)
  13. ↑ Andreas Gröhbühl, Philip Stamp: poisonous plant can die horses ( Memento of 15 June 2009 at the Internet Archive ) , RP online 11 June, 2009
  14. ^ Clara Berendonk: Beware of Jacob's ragwort , Chamber of Agriculture North Rhine-Westphalia, May 25, 2009
  15. ^ A b Pierson ML, Cheeke PR, Dickinson EO (1977): Resistance of the rabbit to dietary pyrrolizidine (Senecio) alkaloid. Res Commun Chem Pathol Pharmacol. 1977 Mar; 16 (3): 561-4. PMID 847303
  16. ↑ PR Cheeke, ML Pierson Goeger: Toxicity of Senecio jacobaea and pyrrolizidine alkaloid in various laboratory animals and avian species . Toxicol Lett. 1983 Sep; 18 (3): 343-9. PMID 6665808
  17. ↑ Hartog: Fighting ragwort ( memento from October 15, 2010 in the Internet Archive ). Viewed on July 20, 2010 on hartog-lucerne.de
  18. ↑ Monika Lahrssen-Wiederholt: Pyrrolizidine alkaloids as undesirable substances in the food chain - example ragwort ( Memento from July 21, 2007 in the Internet Archive ) (PDF; 735 kB), Federal Institute for Risk Assessment Forum Consumer Protection, July 2007
  19. ↑ Robert Hegnauer: Chemotaxonomy of Plants , Birkhäuser, Basel 1989, p. 281: [2]
  20. ↑ A. Dübecke, G. Beckham, C. Lüllmann: Pyrrolizidines alkaloids in honey and bee pollen. In: Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment. Vol. 28, number 3, March 2011, pp. 348-358, ISSN  1944-0057 . doi: 10.1080 / 19440049.2010.541594 . PMID 21360377 .
  21. ↑ Zero tolerances in food and feed, BfR position paper of March 12, 2007; P. 3 (PDF; 205 kB)
  22. ↑ Deutschlandradiokultur.de , meal , August 28, 2011, Udo Pollmer: Nice, but toxic
  23. ^ Press release from July 15, 2013.
  24. ↑ Pyrrolizidine alkaloids in honey
  25. ↑ Beware of the ragwort Homepage Chamber of Agriculture North Rhine-Westphalia
  26. ^ Ragwort - prevention and control (PDF) Federal Institute for Risk Assessment. Retrieved May 17, 2019.
  27. ↑ NABU Schleswig-Holstein: ragwort - poisonous plant in the political minefield. Retrieved August 7, 2018 .
  28. ↑ Maud Grieve: A modern herbal. The medicinal, culinary, cosmetic and economic properties, cultivation and folklore of herbs, grasses, fungi shrubs and trees with all their modern scientific uses . No. 2 . Hafner, Darien, Conn. 1971 (English).
  29. ↑ a b Island Facts. National Flower. (No longer available online.) In: Isle of Man government. May 10, 2007, archived from the original on May 10, 2007 ; accessed on June 30, 2020 (English).