Tender rush

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Tender rush
Tender rush (Juncus tenuis)

Tender rush ( Juncus tenuis )

Systematics
Monocots
Commelinids
Order : Sweet grass (Poales)
Family : Rush Family (Juncaceae)
Genre : Rushes ( Juncus )
Type : Tender rush
Scientific name
Juncus tenuis
Willd.

The Juncus tenuis ( Juncus tenuis ) is a plant from the genus of rushes ( Juncus ) within the family of Juncaceae (Juncaceae). This neophyte , originally from North America and now naturalized, has only been proven in Europe since 1824.

Distribution and location

The rush plant originally comes from North America and occurs there from eastern Canada to Mexico. It has been known in Europe since around 1824. Today the rush is naturalized in northern, western and central Europe and is now distributed worldwide to Asia, South America, New Zealand and Australia. In the Allgäu Alps in Bavaria near Grasgehren near Obermaiselstein it rises up to 1430 meters above sea level.

The tender rush often grows on forest paths and in footsteps. It prefers loam or clay soil that is poor in humus and should be rich in bases but low in lime. It endures soil compaction and moderate shade. In higher low mountain ranges with limestone it is absent in some areas. According to Ellenberg , it is a moderately acidic pointer, growing on moderately nitrogen-rich sites, and a federation character of the bird knotweed stepping societies (Polygonion avicularis). According to Oberdorfer , it is a character species of the Juncetum tenuis.

description

Tender rush ( Juncus tenuis )
Illustration of the tender bulrush

The perennial, wintering green hemicryptophyte forms small yellow-green to brown-yellow clumps with a height of 15 to 50 centimeters. The round stems grow upright. Flowering stems have one or two grass-like, runny and not very stiff leaves at the base, as well as two to three bracts that protrude far above the inflorescence . At the end of the leaf sheaths there are 1 to 3 millimeters long, whitish auricles.

  • Stem with leaves, the auricles at the upper end of the leaf sheath are pointed, delicate, membranous and dry whitish.

  • Inflorescence, each flower has two membranous bracts at the base.

  • Fruit, the tepals are pointed and longer than the fruit.

The always terminal inflorescence is a compact spiral up to 8 centimeters long . The partial inflorescences are long stalked. The tepals are all the same length with 3 to 4 millimeters. They are green, clearly three-veined and lanceolate, pointed. The inner ones are edged with skin. They surround six stamens and three upright long stigmas . The capsule fruit is egg-shaped to spherical and has a short spiked tip. It is significantly shorter than the flower envelope. The seeds are small and pale. They swell like frog spawn in the water.

The flowering time of the tender bulrush extends from June to September.

The number of chromosomes is 2n = 30, 32, 40 or 84.

ecology

The flowers are pollinated by the wind ( anemophilia ). The diaspores are spread by adhering to the fur or feathers of animals ( epizoochory ).

15–40 cm high clump plant. First spread in Europe because of sticky seeds along the unpaved roads through the spread of treads and through the soil adhering to the wagon wheels. If ripe fruit capsules are moistened with water, the seeds emerge like frog spawn after a few minutes . Cultural companion.

literature

  • J. Grau, BP Kremer, BM Möseler, G. Rambold & D. Triebel: Gräser , Mosaik-Verlag, Munich 1996, ISBN 3-576-10702-9 .
  • Henning Haeupler , Thomas Muer: picture atlas of the fern and flowering plants of Germany (= the fern and flowering plants of Germany. Volume 2). Published by the Federal Agency for Nature Conservation. Ulmer, Stuttgart 2000, ISBN 3-8001-3364-4 .
  • E. Oberdorfer: Plant-sociological excursion flora. Ulmer, Stuttgart 1994. ISBN 3-8252-1828-7 .

Individual evidence

  1. ↑ a b Rafaël Govaerts (ed.): Juncus tenuis. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved October 12, 2016.
  2. ↑ Erhard Dörr, Wolfgang Lippert : Flora of the Allgäu and its surroundings. Volume 1, IHW, Eching 2001, ISBN 3-930167-50-6 , p. 297.
  3. ↑ 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.  147 .

Web links

Commons : Zarte Bulse ( Juncus tenuis )  - Collection of images, videos and audio files

Distribution maps