Wild pond cress

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Wild pond cress
Wild pond cress (Rorippa sylvestris), illustration

Wild pond cress ( Rorippa sylvestris ), illustration

Systematics
Eurosiden II
Order : Cruciferous (Brassicales)
Family : Cruciferous vegetables (Brassicaceae)
Tribe : Cardamineae
Genre : Marsh cress ( Rorippa )
Type : Wild pond cress
Scientific name
Rorippa sylvestris
( L. ) Better

The wild pond cress ( Rorippa sylvestris ) is a species of pond cress ( Rorippa ) within the cruciferous family (Brassicaceae).

description

Four-fold bloom in detail
Habit, leaves and inflorescences from above
Habitus
fruit

Appearance and leaf

The wild watercress grows as a wintering green, perennial herbaceous plant and reaches heights of 20 to 60 centimeters. It is a hibernating species with leaf rosettes that drives underground, branched, thin runners . The laying down, upright to ascending stem is branched, glabrous or weakly covered with very short hair.

The foliage leaves are usually divided into petioles and leaf blades and do not encompass the stem. The lower leaves are pinnate to pinnate and have four to seven pairs of serrated to pinnate sections on each side. The upper leaves can be sessile and often have narrower and undivided sections.

Inflorescence, flower and fruit

The flowering period extends mainly from June to October. The racemose inflorescences are rarely more than 10 centimeters long.

The hermaphrodite flowers are fourfold. The four sepals are elliptical to oblong with a length of 2 to 3 millimeters. The four golden yellow, free petals are obovate with a length of 4 to 5 millimeters. There are six stamens . In the base of the crown, two nectaries are inserted between two stamens .

The horizontal or slightly protruding fruit stalks are up to 12 millimeters long. The pods are linear with a length 8 to 18 millimeters and a width of about 1 millimeter, pointed and straight or slightly curved.

Chromosome set

The number of chromosomes is 2n = 32, less often 40 or 48.

ingredients

The roots contain the mustard oil hirsutin .

ecology

The wild pond cress is a hemicryptophyte , more precisely a stem plant . With roots up to 0.75 meters deep and as a crawling pioneer, the wild pond cress can be used for bank reinforcement. There is vegetative reproduction as a lawn-forming creep pioneer and through root shoots or leaf buds. Whole plants can be spread out by flooding.

From an ecological point of view, these are "small funnel-shaped flowers" whose golden yellow petals protrude above the calyx. The stigmas and the anthers of the four longer stamens are at the same height, so that visitors' heads touch both, with self- pollination and cross- pollination . In rainy weather, the corolla opens only halfway, and spontaneous self-pollination takes place through the longer stamens . The pollination is done by insects , such as bumblebees , bees and hoverflies .

There is water spreading of the seeds and fruits, as well as human spreading.

Occurrence

Rorippa sylvestris is distributed from Europe to India and Japan. It is a Eurasian-suboceanic-sub-Mediterranean flora element . It is a neophyte in New Zealand, North and South America.

It can often be found in Austria. In the Allgäu Alps , it rises in Vorarlberg at the foot of the Walmendinger Horn at the Upper Heuberghaus up to an altitude of 1440 meters. In Switzerland it occurs only occasionally. The wild pond cress is mostly common in Germany ; it is only rarely found in west and north-east Germany.

The wild pond cress grows on floodplain - and in rubble weed communities. They are mainly found on banks, in ditches, in fields and in forest nurseries . It thrives best on mostly moist, nutrient-rich, nitrogen-containing, humus soils .

After Erich Oberdorfer is a characteristic species of Rorippo-Agrostietum stoloniferi from the Association Agropyro-Rumicion. According to Heinz Ellenberg , it is a character species of the Association of Riverside Reeds (Phalaridion arundinaceae).

Taxonomy

It was first published in 1753 under the name ( Basionym ) Sisymbrium sylvestre by Carl von Linné . The new combination to Rorippa sylvestris (L.) Besser was published in 1821 by Wilibald Swibert Joseph Gottlieb von Besser . The specific epithet sylvestris means "growing wild".

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 .
  • Wolfgang Adler, Karl Oswald, Raimund Fischer: Excursion flora of Austria . Ed .: Manfred A. Fischer. Eugen Ulmer, Stuttgart / Vienna 1994, ISBN 3-8001-3461-6 .
  • Christian Heitz: School and excursion flora for Switzerland. Taking into account the border areas. Identification book for wild growing vascular plants . Founded by August Binz. 18th completely revised and expanded edition. Schwabe & Co., Basel 1986, ISBN 3-7965-0832-4 .
  • Erich Oberdorfer : Plant-sociological excursion flora . With the collaboration of Theo Müller. 6th, revised and expanded edition. Eugen Ulmer, Stuttgart (Hohenheim) 1990, ISBN 3-8001-3454-3 .
  • Konrad von Weihe (ed.): Illustrated flora. Germany and neighboring areas. Vascular cryptogams and flowering plants . Founded by August Garcke. 23rd edition. Paul Parey, Berlin / Hamburg 1972, ISBN 3-489-68034-0 .
  • Ruprecht Düll , Herfried Kutzelnigg : Pocket dictionary of plants in Germany and neighboring countries. The most common Central European species in portrait . 7th, corrected and enlarged edition. Quelle & Meyer, Wiebelsheim 2011, ISBN 978-3-494-01424-1 .

Individual evidence

  1. ↑ a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas. 8th edition. Page 470. Stuttgart, Verlag Eugen Ulmer, 2001. ISBN 3-8001-3131-5
  2. ^ Rorippa in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved July 23, 2017.
  3. ↑ Erhard Dörr, Wolfgang Lippert : Flora of the Allgäu and its surroundings. Volume 1, IHW, Eching 2001, ISBN 3-930167-50-6 , p. 580.

Web links

Commons : Wild watercress ( Rorippa sylvestris )  - Album with pictures, videos and audio files