Screwy balances

from Wikipedia, the free encyclopedia
Screwy balances
Screwy balances (Ruppia cirrhosa)

Screwy balances ( Ruppia cirrhosa )

Systematics
Class : Bedecktsamer (Magnoliopsida)
Monocots
Order : Frog-spoon-like (Alismatales)
Family : Balaceae (Ruppiaceae)
Genre : Balances ( ruppia )
Type : Screwy balances
Scientific name
Ruppia cirrhosa
( Petagna ) Grande

The screw-like salde (also called beach salde ) ( Ruppia cirrhosa (Pet.) Grande , Syn. Ruppia spiralis L. ex Dumort. ) Is a perennial, evergreen, submerged saltwater plant from the family of the saline plants (Ruppiaceae).

Occurrence

The screwy balance occurs scattered on submarine meadows in shallow coastal waters. In the Baltic Sea, these are mostly wave-exposed locations on sand. However, the plant also colonizes lagoon waters, tidal creeks, saline pools and ditches. Their distribution is limited to the temperate and subtropical latitudes of the northern and southern hemispheres. There it only populates the littoral coastal areas close to the sea. In Germany it is on the red list of vascular plants and is classified there as endangered. No stocks are currently known inland. Their habitat is the plant formation of the salt plant corridors, where they are most commonly found. It is also the characteristic of the association Ruppietum cirrhosae from the association Ruppion maritimae and the class of Ruppietea maritimae.

Screwy balances ( Ruppia cirrhosa ), illustration

Identifying features

The screwed balance is about 15 to 40 cm long and has a thread-like habit. The stem takes root at the nodes. Its narrow, linear, two-lined leaves are only 1 mm wide, blunt, divorced at the base and very finely serrated at the tip. The inconspicuous, hermaphroditic flowers have no inflorescence and are arranged in terminal, two-flowered spikes. The two stamens of each flower cover the very short tepals . There are also 4 free, upper ovaries , which are relatively long stalked like the ear during the flowering period, which is between June and September . The ear stalk can be up to 8 cm long and after fertilization is elongated and rolled up in a spiral. The small fruits are obliquely egg-shaped.

The number of chromosomes of the species is 2n = 40.

ecology

The screwy balance can vegetatively multiply through the formation of above-ground, independently viable runners. We speak of monopodial fragmentation here. The flowers are pollinated by the water. For this purpose, the plant forms a long spike stem, at the tip of which two flowers are formed, which are slightly raised above the surface of the water. The flowers produce pollen that floats on the water surface and is carried to other flowers by the current.

literature

Individual evidence

  1. ↑ Rafaël Govaerts (ed.): Ruppia cirrhosa. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved August 17, 2016.
  2. ↑ a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . 8th edition. Page 106. Stuttgart, Verlag Eugen Ulmer, 2001. ISBN 3-8001-3131-5

Web links

Commons : Ruppia cirrhosa  - album with pictures, videos and audio files