Rice mercury

from Wikipedia, the free encyclopedia
Rice mercury
Rice Mercury (Leersia oryzoides)

Rice Mercury ( Leersia oryzoides )

Systematics
Order : Sweet grass (Poales)
Family : Sweet grasses (Poaceae)
Subfamily : Ehrhartoideae
Tribe : Oryzeae
Genre : Leersia
Type : Rice mercury
Scientific name
Leersia oryzoides
( L. ) Sw.

The rice mercury ( Leersia oryzoides ) is a species from the sweet grass family (Poaceae). Other German names are rice grass , Europe rice wheatgrass , mercury rice and wild rice . The distribution area is in Europe, Asia, Africa, North America and Asia. It is similar to the rice plant and is often found as a weed in rice fields.

description

illustration
The stem nodes are densely hairy.
Stem with foliage and ligule
panicle
Spikelets: glumes absent, cover (Lem) and palea (Pal) are fused together and enclose the flower.

The rice mercury is a perennial and loose lawn-forming sweet grass that forms 10 to 20 centimeters long, subterranean, scale-leaved runners . The renewal shoots grow up outside the lowest leaf sheaths. The stalks are 30 to 100 centimeters high and branched. The internodes are glabrous and the nodes have short hairs. The leaf sheaths are very rough. The ligule is a 1 to 1.5 millimeter long, membranous border. The leaf blade is light green, spread flat, 12 to 30 centimeters long and 4 to 8, sometimes up to 10 millimeters wide. The leaf margin is very rough and cutting, in the lower third of the blade the spiky hairs are directed towards the base, in the upper third towards the tip.

The inflorescence is a 12 to 20 centimeter long and 6 to 14 centimeter wide, loosely spread panicle. In Central Europe, however, it only emerges completely from the uppermost, inflated leaf sheath in the warmest years. The spikelets are single-flowered, oval, 4 to 5 millimeters long, 1.5 to 2 millimeters wide and slightly compressed at the sides. They usually bloom with closed husks and usually fall off as a whole when ripe. The glumes are stunted. The lemma is five-nerved, 4 to 5 millimeters long, ciliate and not awned. The nerves are long, stiff-haired. The palea is three-nerved, 4 to 5 millimeters long and stiff-haired over the middle nerve. Two cavernous bodies are formed per flower . The three anthers of the open flowering spikelets are 1.5 to 1.8 millimeters long, those of the remaining closed 0.5 to 0.8 millimeters. The fruit is 3 millimeters long and 1 millimeter wide and strongly compressed on the sides. The rice mercury blooms from August to October.

The number of chromosomes is 2n = 48.

distribution

The distribution area ranges from Macaronesia , Europe, Siberia and Central Asia to China (occurrence in the provinces of Fujian , Hainan , Heilongjiang , Hunan and Xinjiang ), East Asia and India. They can be found in Australia and New Zealand, and from Canada to the United States to Mexico. In Central Europe it occurs scattered from the lowlands up to an altitude of 1000 meters. It grows in swamp ditches and on banks mostly under reeds. They are often found along the migration routes of water birds. It loves warmth and nitrogen. It is a species of the Leersietum oryzoidis from the Sparganio-Glycerion association.

In Austria it is rare to very rare and is completely absent in East Tyrol . It is considered endangered, in the western federal states as severely endangered.

In Germany the species is also found only very scattered or rarely. The stocks are constantly decreasing due to the draining of swamps. The northern limit of the distribution area is in Schleswig-Holstein , on the Baltic coast it occurs east to Stettin .

Systematics and research history

The rice Quecke ( Leersia oryzoides ) is a type of the Genus Leersia in the family of grasses (Poaceae), there it is the subfamily Ehrhartoideae and tribe Oryzeae assigned. The type was in 1753 by Linnaeus in Species Plantarum as Phalaris oryzoides ( Basionym ) first described , and thus the gloss grass ( Phalaris assigned). Olof Peter Swartz placed them in the newly established genus Leersia in 1788 . The generic name Leersia is reminiscent of the German pharmacist and botanist Johann Daniel Leers (1727–1774) from Herborn . The type epithet oryzoides means "rice-like" and refers to the similarity with the rice plant ( Oryza sativa ).

Further synonyms of the species are Asperella oryzoides (L.) Lam. , Asprella oryzoides (L.) Schreb , Ehrharta clandestina Weber , Homalocenchrus oryzoides (L.) Haller , Oryza clandestina (Weber) A. Braun ex Asch. , Oryza oryzoides (L.) Dalla Torre & Sarnth. and Poa paludosa Honck. .

meaning

The rice mercury is similar to the rice plant and occurs together with it in rice fields but also in corn fields. It is an unpopular weed because it can cut hands while weeding. It is also avoided by cattle because of the sharp leaves.

Individual evidence

  1. ↑ a b c d e f Aichele, Schwegler: Our grasses , p. 100.
  2. ↑ a b c d e f Conert: Pareys Gräserbuch , p. 386.
  3. ^ A b c Fischer, Oswald, Adler: Excursion flora for Austria, Liechtenstein and South Tyrol , p. 1148.
  4. ^ Illustration by Jan Kops (1765–1849) from Flora Batava of Afbeelding en Beschrijving van Nederlandsche Gewassen . 1849.
  5. ↑ a b W.D. Clayton, M. Vorontsova, KT Harman, H. Williamson: Leersia oryzoides. In: GrassBase - The Online World Grass Flora. Royal Botanic Gardens, Kew, accessed November 7, 2014 .
  6. ↑ Shou-liang Chen et al .: Leersia oryzoides in Flora of China , Vol 22.
  7. ^ 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.  264 .
  8. ↑ Leersia oryzoides in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.
  9. ^ Phalaris oryzoides. In: The International Plant Name Index. Retrieved November 8, 2014 .
  10. ↑ Leersia oryzoides. In: The International Plant Name Index. Retrieved November 8, 2014 .
  11. ↑ Rafaël Govaerts (Ed.): Leersia oryzoides. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved May 23, 2020.

literature

  • Hans Joachim Conert: Parey's grass book . Recognize and determine the grasses of Germany. Blackwell Wissenschafts-Verlag, Berlin, Vienna 2000, ISBN 3-8263-3327-6 , pp. 386, 387 .
  • Aichele, Schwegler: Our grasses . Over 400 color drawings. Updated 12th edition. Franckh-Kosmos, Stuttgart 2011, ISBN 978-3-440-12573-1 , p. 100 .
  • Wu Zheng-yi, Peter H. Raven, Deyuan Hong (Eds.): Flora of China . Volume 22: Poaceae . Science Press / Missouri Botanical Garden Press, Beijing / St. Louis 2006, ISBN 1-930723-50-4 , pp. 184 (English, online ).
  • Manfred A. Fischer , Karl Oswald, Wolfgang Adler: Excursion flora for Austria, Liechtenstein and South Tyrol. 3rd, improved edition. State of Upper Austria, Biology Center of the Upper Austrian State Museums, Linz 2008, ISBN 978-3-85474-187-9 , p. 1148.

Web links

Commons : Rice Mercury ( Leersia oryzoides )  - Collection of images, videos and audio files