Blunt-edged water star

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Blunt-edged water star
Blunt-edged water star (Callitriche cophocarpa)

Blunt-edged water star ( Callitriche cophocarpa )

Systematics
Asterids
Euasterids I
Order : Mint family (Lamiales)
Family : Plantain family (Plantaginaceae)
Genre : Water stars ( callitriche )
Type : Blunt-edged water star
Scientific name
Callitriche cophocarpa
Sendtn.
Floating leaf rosette with male flowers

The blunt-edged water star ( Callitriche cophocarpa ) belongs to the plantain family (Plantaginaceae). The plant forms completely submerged water forms, but also land forms, whereby the transition is very easy and fluid and is also reversible. The shape of the plants, especially the leaves, is constantly changing.

description

The blunt-edged water star is a hibernating green, perennial , submerged aquatic plant ( hydrophyte ) with up to 25 centimeters long stems and mostly with floating leaf rosettes. Alternatively, he lives as an annual therophyte crawling in the mud . The up to 2 centimeters long diving leaves of the water forms are variable. The floating leaves are narrowly rhombic to elliptical in shape. They are six to ten, more rarely up to sixteen in dense rosettes 2 to 3 centimeters in diameter. The landforms grow grass-like. Their leaves are usually smaller and coarser than those of the water forms. They do not have pronounced floating leaf rosettes. Only the land forms and the floating leaves of the water forms have stomata . The plants are anchored with their roots at the bottom of their growing waters. The landforms take root on the older stem parts when they sink to the ground; the intermediate pieces die off. This is how independent plants develop.

The flowering period extends from May to September. The inconspicuous flowers are separate sexes; they stand in the axils of the floating leaves. The male flowers have a long, 1 millimeter wide stamen with yellowish pollen , the female each have an ovary and two stigmas . The 1 to 1.1 millimeter long fruits are rounded. The partial fruits are blunt-edged or weakly keeled.

The species has chromosome number 2n = 10 or 12.

Distribution and location

The range of the species includes Europe and western Asia with a focus on northern, central and eastern Europe. There the blunt-edged water star grows in mostly nutrient-rich, more rarely in nutrient-poor, standing and flowing waters, such as backwaters, ponds and streams. The plant prefers to settle in shallower parts of the water, which can also dry out, but are at least permanently wet and mostly flooded. The formation of the different forms thus represents a vital adaptation. In Central Europe, the blunt-edged water star is a character species of the Ranunculo trichophylli-Sietum erecto-submersi from the Ranunculion fluitantis association, but occurs less often in societies of the order Potamogetonetalia or Littorelletalia.

In the Allgäu Alps, the species rises in a pond in Vorarlberg between Widderstein and Seekopf up to 2000 m above sea level.

Systematics

The blunt-edged water star ( Callitriche cophocarpa Sendtner ) has the synonym: Callitriche polymorpha Lönnr.

literature

  • Henning Haeupler, Thomas Muer: picture atlas of the fern and flowering plants of Germany . Published by the Federal Agency for Nature Conservation (=  The fern and flowering plants of Germany . Volume 2 ). 2nd corrected and enlarged edition. Eugen Ulmer, Stuttgart (Hohenheim) 2007, ISBN 978-3-8001-4990-2 .
  • Heiko Bellmann: Life in brook and pond. Orbis, Munich 2000, ISBN 3-572-01085-3 .

Individual evidence

  1. ↑ a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . 8th edition. Stuttgart, Verlag Eugen Ulmer, 2001. Page 790. ISBN 3-8001-3131-5
  2. ↑ Erhard Dörr, Wolfgang Lippert : Flora of the Allgäu and its surroundings. Volume 2, IHW, Eching 2004, ISBN 3-930167-61-1 , p. 197.

Web links

Commons : Blunt-edged Water Star  - Collection of images, videos and audio files