Swamp water star

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Swamp water star
Callitriche palustris.jpg

Swamp water star ( Callitriche palustris )

Euasterids I
Order : Mint family (Lamiales)
Family : Plantain family (Plantaginaceae)
Tribe : Callitricheae
Genre : Water stars ( callitriche )
Type : Swamp water star
Scientific name
Callitriche palustris

The sump water rating ( Callitriche palustris ), also spring-water rating called, is a plant species that for the genus of callitriche ( Callitriche ) within the family of Plantain Family belongs (Plantaginaceae). This marsh and aquatic plant is widespread in the northern hemisphere .


Illustration from Otto Wilhelm Thomé: Flora of Germany, Austria and Switzerland , Gera 1885.
Swamp water star ( Callitriche palustris ): floating leaf rosettes with flowers

The swamp water star grows as an annual to wintering green, perennial herbaceous plant . On the parts of the plant that reach the surface of the water, floating leaves are formed in star-shaped rosettes. The diving leaves are mostly narrow oval and hardly differ from the land leaves.

The flowering period extends from April to September. The inconspicuous flowers are relatively small. The stamens are only about 5 millimeters long. The split or broken fruit disintegrates into four relatively small, stone-like cusps. These are black when ripe and narrowed towards the base. They only have wings at the top and bottom. The pre-leaves are ephemeral or even absent.

The number of chromosomes is 2n = 20.


The swamp water star is a type of abandoned mud bottom that rarely penetrates deeper water. The species avoids running water. It is a mud root in water and can form lawns. She is amphibious ; it is viable both submerged in water and on moist soil. As a water plant , it usually ends with a floating rosette of leaves. Stomata are missing on the underwater leaves; On the floating leaves there are stomata on both the upper and lower sides, on the air leaves only on the underside. A Vegetative propagation is done by torn shoot parts.

There is wind pollination or, in the case of underwater flowers, also water pollination ; in this case the pollen rises to the scars on the water surface.

The Klausen are subject to swimming and, with the help of the scarring, also to Velcro spread by water birds. Fruit ripening takes place from August.


The swamp water star occurs throughout Europe, North Africa, temperate Asia and North America. In ponds, lakes and pools, it usually grows at water levels up to about 30 centimeters. Drained ponds or wet tracks in the forest are typical. In Central Europe it is a character species of the Hottonietum palustris from the Nymphaeion albae association. But it also occurs in other societies of the Nymphaeion or the class of Strandling societies (Littorelletea). In the Allgäu Alps, it rises in the Tyrolean part on the Mutte above Bernhardseck near Elbigenalp to an altitude of 2150 meters.


Individual evidence

  1. Swamp Water Star. In: FloraWeb.de.
  2. a b c d e Ruprecht Düll , Herfried Kutzelnigg : Pocket dictionary of plants in Germany and neighboring countries. The most common Central European species in portrait . 7th, corrected and enlarged edition. Quelle & Meyer, Wiebelsheim 2011, ISBN 978-3-494-01424-1 .
  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.  790 .
  4. 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 : Swamp Water Star  - Album with pictures, videos and audio files