Small duckweed

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Small duckweed
Lesser duckweed (Lemna minor)

Lesser duckweed ( Lemna minor )

Systematics
Monocots
Order : Frog-spoon-like (Alismatales)
Family : Arum family (Araceae)
Subfamily : Duckweed family (Lemnoideae)
Genre : Duckweed ( Lemna )
Type : Small duckweed
Scientific name
Lemna minor
L.
Water with duckweed on the Darß
Botanical illustration of the small duckweed
Duckweed carpet with limnobium in the aquarium
Duckweed carpet in the aquarium

The small duckweed ( Lemna minor L. ) is one of 14 species of the genus duckweed ( Lemna ), which has recently been added to the araceae family (formerly: Lemnaceae).

description

Duckweed usually consists of one or more "leaflets" (actually phyllocladia ) that contain air-filled cavities that allow them to swim freely on or just below the surface of the water. From there a root grows into the water, with which minerals can be absorbed and which, like a boat keel, contributes to the floating stability of the plant. Special cells, so-called idioblasts , are rich in oxalate needles and perhaps serve to protect against snail damage.

The small duckweed, which in its vegetative state is difficult to distinguish from the hunchbacked duckweed , rarely blooms here. The flowers are "pollen disc flowers " with water pollination . Above water bloomers experience random pollination by water striders , spiders and snails . The flowers are greatly reduced and very small; the male consist only of a stamen, the female only a pistil with a funnel-shaped stigma. The flowering period extends from May to June.

The fruits are nuts with one or more seeds. The approx. 1 mm long seeds experience a swimming spread.

The number of chromosomes is 2n = 40.

ecology

The small duckweed reproduces asexually by sprouting , in which the laterally growing shoots either remain connected to the mother plant or become independent. It stores starch in autumn and then sinks to the frost-free ground for winter.

General distribution

The lesser duckweed is widespread in the temperate areas of North America , Eurasia, and Africa ; it is naturalized in Australia and New Zealand . In Europe, their occurrence extends north to about 66 degrees north latitude. In the Allgäu Alps, it rises in a pond near the Dinigörgen-Alpe near Rohrmoos in Bavaria up to 1250 meters above sea level.

Locations

The small duckweed is widespread and often found in stagnant bodies of water such as ponds and ponds, which it soon completely covers with its approximately three millimeter long and oval-shaped floating leaves if there is a sufficient supply of nutrients; it forms a plant community (sometimes together with other species of the duckweed family ). As a result, only little light enters the water, which prevents submerged plants from growing and, for example, also influences the water temperature. The small duckweed is a species of the Lemnetum minoris from the Lemnion minoris association. It occurs up to a water depth of 250 centimeters.

Naming and use

In popular parlance, the duckweed or duckweed family is also known as duckweed, duck greens or duck floss, as it is a welcome source of food for ducks and geese , but also for fish. Their dry matter is actually very rich in protein and starch and poor in raw fiber. Therefore it is / was even used as fodder.

The protein of the small duckweed is comparable to that of the soybean in the composition of its amino acids and because of its high content of trace elements . That is why the species is also recommended as a wild vegetable for humans. Since the plant effectively stores minerals, however, its radium content can be 100 to 600 times as high as in the water that surrounds it. If, for example, ducks mainly feed on these duckweed, the radium concentration in their meat can be up to ten times higher and this can be a potential danger for people who eat such meat.

literature

  • 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 .
  • Elfrune Wendelberger: Plants of the wetlands. BLV-Intensivführer, Munich 1986. ISBN 3-405-12967-2 .
  • 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 .
  • Oskar Sebald, Siegmund Seybold, Georg Philippi: The fern and flowering plants of Baden-Württemberg . Volume 8, Ulmer Verlag.

Individual evidence

  1. ↑ Rafaël Govaerts (ed.): Lemna - World Checklist of Selected Plant Families des Royal Botanic Gardens, Kew. Last accessed on June 18, 2018.
  2. ↑ Christel Kasselmann : aquarium plants. Ulmer Verlag, Stuttgart 1995; 2nd, revised and expanded edition 1999, ISBN 3-8001-7454-5 , p. 328.
  3. ↑ a b c 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. 120 .
  4. ↑ Erhard Dörr, Wolfgang Lippert : Flora of the Allgäu and its surroundings. Volume 1, IHW, Eching 2001, ISBN 3-930167-50-6 , p. 291.

Web links

Commons : Small duckweed ( Lemna minor )  - album with pictures, videos and audio files