Small-leaved watercress

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Small-leaved watercress
Small-leaved watercress (Nasturtium microphyllum)

Small-leaved watercress ( Nasturtium microphyllum )

Systematics
Eurosiden II
Order : Cruciferous (Brassicales)
Family : Cruciferous vegetables (Brassicaceae)
Tribe : Cardamineae
Genre : Watercress ( nasturtium )
Type : Small-leaved watercress
Scientific name
Nasturtium microphyllum
Boenn. ex Rchb.

The small-leaved watercress ( Nasturtium microphyllum ) is a species of the cruciferous family (Brassicaceae).

Small-leaved watercress in flower

description

Appearance and leaf

The small-leaved watercress grows as a perennial herbaceous plant with heights of (10 to) 20 to 100 (to 180) centimeters. The aboveground parts of the plant are hairy bald or slightly downy. The fleshy and hollow stems are prostrate in the lower area and branch out at the lower internodes into ascending or sometimes flowing shoots.

The alternate leaves are divided into a petiole and a leaf blade. The petiole is not winged, but is often eyed at its base . The imparipinnate leaf blade has (three to) five to nine (up to eleven) leaf pinna. This is with an wingless leaf rhachis (1.5 to) 2.5 to 10 (to 15) centimeters long. The lateral, sessile or stalked leaflets are smaller than the almost circular or broadly elliptical to elongated leaflets . The latter are (0.6 to) 1.5 to 3.5 (to 4.5) centimeters long and (4 to) 8 to 20 (up to 25) millimeters wide, blunt, wedge-shaped or almost heart-shaped at the base of the spade; the leaf margin is wavy or entire and the upper end is blunt. Stipules are absent.

Inflorescence and flower

The flowering period extends from January to August. The flowers are grouped in racemose inflorescences that are elongated when the fruit is ripe . The (7 to) 9 to 21 (to 25) millimeter long pedicels are descending, straight or sometimes slightly bent back.

The hermaphroditic flowers are fourfold and radial symmetry . The four free sepals standing in two circles have a length of 2.5 to 4 millimeters and a width of 1 to 1.5 millimeters. The four free, white or pink petals are 4 to 6 millimeters long and 1.5 to 3 millimeters wide, spatulate or obovate with a rounded upper end. The six stamens standing in two circles consist of 2.5 to 3.5 millimeter long stamens and yellow, 0.7 to 1 millimeter long anthers. In each above-permanent ovary there are 30 to 38 (rarely to 40) ovules .

Fruit and seeds

The seeds are arranged in a single row in the pods , which are 14 to 30 millimeters long and 1 to 2 millimeters wide . The red-brown seeds are egg-shaped with a length of (0.8 to) 1 to 1.2 millimeters and a diameter of (0.6 to) 0.7 to 0.8 (to 0.9) millimeters. The seed surface has a network-like structure with (75 to) 100 to 150 (to 175) polygonal spots on each side.

Chromosome number

The number of chromosomes in small-leaved watercress is 2n = 64.

Occurrence and endangerment

The original home of the small-leaved watercress is in Europe , in north-west African Morocco , in west Asian Iran and Afghanistan as well as in northern Pakistan and north-west India . It was introduced as a neophyte on the American continent , Yemen , Japan , Australia and New Zealand .

It is considered endangered in some federal states of Germany and is listed in the respective red lists of the federal states. The Swiss deposits are also described as endangered. The occurrences in the Austrian federal states of Upper Austria , Salzburg , northern Tyrol , Vorarlberg and possibly in Lower Austria are rare. The species is considered endangered and is listed in the Red Lists of Austria in endangerment level 3.

The small-leaved watercress colonizes wet habitats such as lake shores, ponds , springs , river banks, depressions or wet meadows at altitudes from 0 to 1500 meters. In Central Europe it is a character species of the Nasturtietum microphylli from the Sparganio-Glycerion fluitantis association.

Systematics

Nasturtium microphyllum was first described in 1832 by Clemens Maria Franz von Boenninghausen in Ludwig Reichenbach's Flora Germanica Excursoria . Synonyms for Nasturtium microphyllum Boenn. ex Rchb. among others Nasturtium uniseriatum H.W.Howard & Manton , Pirea olgae T.Durand ex Prantl and Rorippa microphylla ( Boenn. ex Rchb. ) H.Hyl.

The small-leaved watercress, like the real watercress, is a parent of the naturally occurring hybrid bastard watercress or sterile watercress ( Nasturtium × sterile ( Airy Shaw ) Oefelein , Syn .: Rorippa × sterilis Airy Shaw ).

literature

  • Ihsan A. Al-Shehbaz: Brassicaceae . In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico . Volume 7: Magnoliophyta: Salicaceae to Brassicaceae . Oxford University Press, New York / Oxford a. a. 2010, ISBN 978-0-19-531822-7 , Nasturtium microphyllum , p. 490 (English, online ). (Sections Description and Distribution)
  • DH Valentine: Nasturtium microphyllum In: TG Tutin, NA Burges, AO Chater, JR Edmondson, VH Heywood, DM Moore, DH Valentine, SM Walters, DA Webb (eds.): Flora Europaea . 2nd, revised edition. Volume 1: Psilotaceae to Platanaceae . Cambridge University Press, Cambridge / New York / Melbourne 1993, ISBN 0-521-41007-X , pp. 346 (English, limited preview in Google Book Search - from the unchanged reprint from 2010 ( ISBN 978-0-521-15366-9 )).

Individual evidence

  1. ↑ a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . 8th edition. Verlag Eugen Ulmer, Stuttgart 2001, ISBN 3-8001-3131-5 . Page 468.
  2. ↑ Karol Marhold: Brassicaceae. Nasturtium microphyllum. In: Euro + Med Plantbase - the information resource for Euro-Mediterranean plant diversity. Botanical Garden and Botanical Museum Berlin-Dahlem, 2011, accessed on February 13, 2012 (English). with distribution map .
  3. ↑ a b Nasturtium in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved July 22, 2017.
  4. ↑ Small-leaved watercress. In: FloraWeb.de. last accessed February 13, 2012 with distribution map for Germany and hazard and protection information .
  5. ^ Nasturtium microphyllum. In: Info Flora - The national data and information center for Swiss flora. Retrieved February 13, 2012 . as well as the red list .
  6. ^ A b Manfred A. Fischer, Karl Oswald, Wolfgang Adler: Excursion flora for Austria, Liechtenstein and South Tyrol . 3rd, improved edition. Province of Upper Austria, Biology Center of the Upper Austrian State Museums, Linz 2008, ISBN 978-3-85474-187-9 , p. 636 .
  7. ↑ Heinrich Gottlieb Ludwig Reichenbach: Flora Germanica excursoria ex affinitate regni vegetabilis naturali disposita, sive principia synopseos plantarum in Germania terrisque in Europa media adjacentibus sponte nascentium cultarumque frequentius. Volume 2, Carl Cnobloch , Leipzig 1832, p. 683 (online) .
  8. ^ Nasturtium microphyllum , synonyms at Tropicos.org. Missouri Botanical Garden, St. Louis, accessed February 13, 2012.

Web links

Commons : Small-leaved watercress ( Nasturtium microphyllum )  - album with pictures, videos and audio files