Equisetum

Young woodland horsetail ( Equisetum sylvaticum )

The horsetails ( Equisetum ) are the only extant genus in the class of Equisetopsida within the ferns.

Horsetails often grow on moist soil or in water. The Horsetail is considered a " weed ", but is also an important medicinal plant.

Description

The species of horsetails ( Equisetum ), with the exception of a tropical nature, not higher than 2 meters.

Horsetails are perennial plants that are vegetatively propagated with their rhizomes.

They are easily recognizable by its rungs. Each rung is made up of a series of nodes ( nodes ) with intervening internodes. At each node spring inconspicuous leaves ( Mikrophylle ), and in some species also side shoots. Both the leaves and the branches are arranged in whorls.

As hygrophytes have the most species at the tips of Mikrophylle hydathodes, which serve the increased water delivery.

The name horsetail stems from the fact that you can pull out the stem axis of the sheath formed by the leaves and insert it back again. Rhizomes are up to 6 m long. Propagation is possible by stolons and by individual, chopped sprout pieces.

The spore cases ( sporangia ) are located on the fifth to tenth on the bottom of the sporangium ( " sporophylls " ) that look like one-legged table. These are arranged spirally in peg-shaped Sporophyllständen at the shoot tip. The spores are always created equal, regardless of gender ( Isospory ). The fossil Calamiten were heterosporous part, so it is assumed that the heterospory was lost. They have the outer layer ( exospore ) two bands ( Hapteren ) having spatulate ends which are wrapped helically in a moist state to the spore. Drying the spores, so unfold the Hapteren and thus cause a Verklettung with each other. Some species carry the Sporophyllstände the green shoots, while others have special (not green ) shoots exclusively for propagation.

System

Since different species of this genus form fertile hybrids, the exact number of species is controversial. Today, it is a total of 15 to 20 species.

  • Subgenus Hippochaete (Milde ) Baker: Equisetum debile Roxb. ex Vaucher ( debile ( Roxb. subsp as subspecies. Vaucher ex ) Hauke ​​to Equisetum ramosissimum provided).
  • Equisetum giganteum L., Origin: tropical South America.
  • Horsetail ( Equisetum hyemale L.), Origin: Europe, Asia, North and Central America.
  • Equisetum laevigatum A. Brown, Origin: North America, Mexico.
  • Equisetum myriochaetum Schltdl. & Cham, home. America.
  • Branched Horsetail ( Equisetum ramosissimum Desf. ), Europe, Asia, Africa, America.
  • Bins shaped or dwarf horsetail horsetail ( Equisetum Scirpoides Michx. ), Origin: Scandinavia, Russia, Asia, North America.
  • Colorful horsetail ( Equisetum variegatum Schleich ex F. Weber & D. Mohr. ), Origin: Europe, Asia, North America, Greenland.
  • Subgenus Equisetum: Horsetail ( Equisetum arvense L.), Origin: Europe, Asia, North America, Greenland.
  • Equisetum bogotense Kunth, Origin: South and Central America.
  • Equisetum diffusum D. Don, Origin: South East Asia.
  • Pond horsetail ( Equisetum fluviatile L.; Syn: E. limosum L.), Origin: Europe, Asia, North America.
  • Marsh horsetail, Duwock ( Equisetum palustre L.), Origin: Europe, Asia, North America.
  • Meadow Horsetail ( Equisetum pratense Ehrh. ), Origin: Europe, Asia, North America.
  • Woodland horsetail ( Equisetum sylvaticum L. ), Europe, Asia, North America, Greenland.
  • Giant horsetail ( Equisetum telmateia Ehrh; Syn. E. maximum auct. ), Origin: Europe, North Africa, Middle East, North America.
  • Hybrids: Equisetum × dycei C.N. Page (E. fluviatile x E. palustre ), Origin: Great Britain, Germany.
  • Shore Horsetail ( Equisetum × litorale Kühlew ex Rupr, E. arvense x E. fluviatile. . ), Origin: Europe. Asia, North America.
  • Southern horsetail ( Equisetum × meridional (Milde ) Chiov. ), Origin: Switzerland, Northern Italy, the Czech Republic, Slovakia.
  • Moores horsetail ( Equisetum × moorei Newman, E. hyemale x E. ramosissimum )
  • Rough Horsetail ( Equisetum × trachyodon ( A. Braun ) WDJ Koch, E. hyemale x E. variegatum )

See also: Systematics of the plant kingdom

Paleobotany

Today's horsetails are the last survivors of a once species- rich group within the vascular spore plants ( Pteridophyta ), the Equisetopsida. At this taxon included the Calamiten ( Calamitaceae ), which are known by fossils from the Permian and Carboniferous. They were lignified, reaching stature heights of up to 30 meters and 1 meter diameter trunk and formed an important part of the coal forests. The first horsetails were in the upper Devonian before about 375 million years ( Pseudobornia bronni ). The horsetails can therefore be referred to as "living fossils".

Use

Medicinally only the barren summer fronds of arable horsetail are ( Equisetum arvense ) is used as a diuretic and used for rheumatism, inflammation, kidney disease, urinary gravel, formerly with tuberculosis. After Kneipp horsetail has very contractive forces; they purify blood, stomach, kidneys and bladder, but also externally cleansing and astringent with rash and sores.

A peculiarity of horsetails is the dispersion of silicon (as Ligninersatz ) in the cell wall. The plant contains up to 7% silica. These inclusions make horsetails to a gentle abrasives ( horsetail ).

Louis Claude Richard Guttation Calamites Scoopula Eduard Strasburger
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