Speared milfoil

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Speared milfoil
Speared milfoil (Myriophyllum spicatum), illustration

Speared milfoil ( Myriophyllum spicatum ), illustration

Systematics
Eudicotyledons
Nuclear eudicotyledons
Order : Saxifragales (Saxifragales)
Family : Millennial family (Haloragaceae)
Genre : Milfoil ( Myriophyllum )
Type : Speared milfoil
Scientific name
Myriophyllum spicatum
L.

The spiked water milfoil ( Myriophyllum spicatum ), also Ährenblütiges milfoil called, is a aquatile plant from the family of haloragaceae (Haloragaceae). Except for the flowers, it grows completely submerged. It has a large distribution area in the northern hemisphere.

description

The milfoil is a perennial water plant and can be around 40 to 200 centimeters long. The plant roots with a rhizome in about 1 to 5 m water depth. The branched stems are reddish or brownish and have a few light green warts. In the shoot there is also a well-developed ventilation tissue ( aerenchyma ). The finely pinnate stem leaves are usually four (rarely five or three) in whorls. They are divided into 14 to 40 thread-like or bristle leaflets, which are more or less arranged opposite one another. The annual inflorescences , which always protrude above the water during flowering, are 4 to 16 cm long. Four of the flowers are arranged in whorls, they are pink or, rarely, white. In the lower part of the inflorescence there are female flowers, in the upper part there are male flowers, rarely there are also hermaphrodite flowers. The upper bracts of the whorls are rounded and undivided, shorter than the flowers, the lower ones can be incised to pinnate-shaped. The male flowers consist of a whole-margined support leaf, a bell-shaped, four-lobed calyx cut to the middle, four petals and eight stamens. The supporting leaflet of the female flowers is divided like a comb, their calyx is tubular, petals are usually missing or are very small. The feathery, pink scar sits on a short stylus . The four-part fruit is about 2 mm in size.

The number of chromosomes is 2n = 28, 36 or 42.

Speared milfoil ( Myriophyllum spicatum )

Occurrence

The wheat milfoil is found quite often in diving-leaf societies, eutrophic , also polluted, rather calcareous, stagnant water with silty subsoil. It not only grows in Germany, but is distributed in a circumpolar manner and occurs all over the northern hemisphere. There are stocks not only in North Africa , but also in Somalia and in the Asian region in the Philippines . It is particularly common in fresh water , but also occurs in brackish water .

In the Alps, the milfoil rises up to 930 m, in Pakistan it can be found from 1000 to 2500 m and in China up to 4200 m, in some sources in Tibet even up to 5200 m.

The spiked water milfoil is a characteristic species of plant sociological order of freshwater pondweed companies (Potamogetonetalia).

ecology

The milfoil is a submerged, free-swimming aquatic plant anchored in the ground with a rhizome as a mud root . It has an aerenchyma for gas exchange and buoyancy . Lime particles are often deposited on their leaves. The flowers are pollinated via water. The pollen is usually transferred to the other plants by the wind, more rarely by insects, where fertilization then occurs. Flowering time is from June to August.

The resulting split fruits, which disintegrate into four small nuts, are spread over the water. Fruit ripens in October.

In contrast to the whorled thousand-leaf , the wheat thousand-leaf does not form winter buds ( turions ).

Aquaristics

The milfoil is occasionally kept as an ornamental plant in aquariums.

Hazards and protective measures

Since there are no known threats to the existence of this species, it is listed by the IUCN in the Least Concern category.

photos

  • The leaves are pinnate in a comb and later encrusted with lime

  • The inflorescence rises above the surface of the water

  • Detailed view of the spike-shaped inflorescence with male flowers above and female flowers below

  • Flower whorls with four female flowers

  • Flower whorls with four male flowers

Individual evidence

  1. ↑ a b c d e f g 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 , p. 323.
  2. ↑ a b c d e Shahina A. Ghazanfar: Myriophyllum spicatum . In: SI Ali, M. Qaiser (Ed.): Flora of Pakistan . Haloragidaceae. Missouri Botanical Garden Press, St. Louis, S. 2 ( eFloras.org ).
  3. ↑ a b c d e f 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.  691 .
  4. ↑ a b c d e Jiarui Chen, Michele Funston: Myriophyllum spicatum . In: Wu Zhengyi, Peter H. Raven (Ed.): Flora of China . tape 13 . Missouri Botanical Garden Press, St. Louis 1994, pp. 430 ( eFloras.org ).
  5. ↑ Myriophyllum spicatum in the IUCN Red List of Threatened Species 2013.2. Listed by: Lansdown, RV, 2012. Retrieved May 14, 2014.

literature

Web links

Commons : Ähriges thousand-leaf  album with pictures, videos and audio files