? Horsetail
Vegetative stem of Equisetum telmateia with a whorl (at each node) of branches and dark-tipped leaves
Scientific classification
Kingdom: Plantae Division: Equisetophyta Class: Equisetopsida Order: Equisetales Family: Equisetaceae Genus: Equisetum
Species
See text

The horsetails are vascular plants, comprising 15 species of plants in the genus Equisetum. This genus is the only one in the family Equisetaceae, which in turn is the only family in the order Equisetales and the class Equisetopsida. This class is often placed as the sole member of the Division Equisetophyta (also called Arthrophyta in older works), though some recent molecular analyses place the genus within Pteridophyta, related to Marattiales. The molecular data, however, are somewhat ambiguous as of yet. Other classes and orders of Equisetophyta are known from the fossil record, where they were important members of the world flora during the Carboniferous period. Download high resolution version (600x800, 103 KB)Equisetum cf. ... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms (as opposed to folk taxonomy). ... Divisions Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta - liverworts Anthocerotophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta - flowering plants Adiantum pedatum (a fern... Divisions Non-seed-bearing plants Equisetophyta Lycopodiophyta Psilotophyta Pteridophyta Superdivision Spermatophyta Pinophyta Cycadophyta Ginkgophyta Gnetophyta Magnoliophyta The vascular plants are those plants that have specialized cells for conducting water and sap within their tissues, including the flowering plants, conifers and other gymnosperms, but not mosses, algae, and the like (nonvascular... In biology, a genus (plural genera) is a taxonomic grouping. ... Classes Marattiopsida Osmundopsida Gleicheniopsida Pteridopsida A fern, or pteridophyte, is any one of a group of some twenty thousand species of plants classified in the Division Pteridophyta, formerly known as Filicophyta. ... Orders Marattiales Christenseniales The Marattiopsida are primitive ferns that are largely quite different from many of the plants that are familiar to people in temperate zones. ... A fossil Ammonite Fossils (from Latin fossus, literally having been dug up) are the mineralized or otherwise preserved remains or traces (such as footprints) of animals, plants, and other organisms. ... In Botany a Flora (or Floræ) is a collective term for plant life and can also refer to a descriptive catalogue of the plants of any geographical area, geological period, etc. ... The Carboniferous is a major division of the geologic timescale that extends from the end of the Devonian period, about 359. ...

Vegetative stem: N = node, I = internode, B = branch in whorl, L = fused megaphylls

The name horsetail arose because it was thought that the stalk resembled a horse's tail; the name Equisetum is from the Latin equus, "horse", and seta, "bristle". Other names, rarely used, include candock (applied to branching species only), and scouring-rush (applied to the unbranched or sparsely branched species). The name scouring-rush refers to its rush-like appearance and because the stems are coated with abrasive silica that led them to be used for scouring cooking pots in the past. Lighten image (hope this is an improvement). ... Lighten image (hope this is an improvement). ... Latin is an ancient Indo-European language originally spoken in the region around Rome called Latium. ... Candock is a common name of two different plants, horsetail and water lily. ... The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ...

The genus is near-cosmopolitan, being absent only from Australasia and Antarctica. They are perennial plants, either herbaceous, dying back in winter (most temperate species) or evergreen (some tropical species, and the temperate Equisetum hyemale). They mostly grow 0.2-1.5 m tall, though E. telmateia can exceptionally reach 2.5 m, and the tropical American species E. giganteum 5 m, and E. myriochaetum 8 m. A cosmopolitan distribution is a term applied to a biological category of living things meaning that this category can be found anywhere around the world. ... It has been suggested that this article or section be merged with Oceania. ... A Red Valerian, a perennial plant. ... This article is about the plants used in cooking and medicine. ... A Silver Fir shoot showing three successive years of retained leaves In botany, an evergreen plant is a plant which retains its leaves year-round, with each leaf persisting for more than 12 months. ...

In these plants the leaves are greatly reduced, being represented only by whorls of small, translucent scales. The stems are green and photosynthetic, also distinctive in being hollow, jointed, and ridged (with (3-) 6-40 ridges). There may or may not be whorls of branches at the nodes; when present, these branches are identical to the main stem except smaller. The leaves of a Beech tree A leaf with laminar structure and pinnate venation In botany, a leaf is an above-ground plant organ specialized for photosynthesis. ... Look up whorl in Wiktionary, the free dictionary. ... The leaf is the primary site of photosynthesis in plants. ...

The spores are borne in cone-like structures (strobilus, pl. strobili) at the tips of some of the stems. In many species they are unbranched, and in some (e.g. E. arvense) they are non-photosynthetic, produced early in spring separately from photosynthetic sterile stems. In some other species (e.g. E. palustre) they are very similar to sterile stems, photosynthetic and with whorls of branches. Spores produced in a sporic life cycle. ...

Strobilus of E. telmateia, terminal on an unbranched stem

Horsetails are mostly homosporous, though in E. arvense, smaller spores give rise to male prothalli. The spores have four elaters that act as moisture-sensitive springs, ejecting the spores through a weak spot of the sporangia. Download high resolution version (500x861, 75 KB)Equisetum telmateia (ID by MPF) cone photographed by Eric Guinther in Portland, Oregon (along roadway just upslope of the zoo) on April 25, 2004. ... Download high resolution version (500x861, 75 KB)Equisetum telmateia (ID by MPF) cone photographed by Eric Guinther in Portland, Oregon (along roadway just upslope of the zoo) on April 25, 2004. ... In plants, a characteristic where the plant produces only one kind of spore. ... Spores produced in a sporic life cycle. ... An elater is a cell (or structure attached to a cell) that is hygroscopic, and therefore will change shape in response to changes in moisture in the environment. ... A sporangium (pl. ...

Many plants in this genus prefer sandy soils, though some are aquatic and others adapted to wet clay soils. One horsetail, E. arvense, can be a nuisance weed because it readily regrows after being pulled out. The stalks arise from rhizomes that are deep underground and almost impossible to dig out. It is also unaffected by many herbicides designed to kill seed plants. The foliage is poisonous to grazing animals if eaten in large quantities. Patterns in the sand Sand is an example of a class of materials called granular matter. ... Soil is the material on the surface of a lithosphere subject to weathering, and especially the earthy portion of that material. ... The Gay Head cliffs in Marthas Vineyard are made almost entirely of natural clays. ... A weed is an unwanted plant. ... Ginger rhizome In botany, a rhizome is a usually-underground, horizontal stem of a plant that often sends out roots and shoots from its nodes. ... A herbicide is a pesticide used to kill unwanted plants. ... The spermatophytes comprise those plants that produce seeds. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

The horsetails were a much larger and more diverse group in the distant past before seed plants became dominant across the Earth. Some species were large trees reaching to 30 m tall. The genus Calamites (Family Calamitaceae) is abundant in coal deposits from the Carboniferous period. The spermatophytes comprise those plants that produce seeds. ... The coniferous Coast Redwood, the tallest tree species on earth. ... Species See text Calamites is a genus of extinct arborescent (tree-like) horsetails to which the modern horsetails (genus Equisetum) are closely related. ... Calamitaceae is an extinct family of plants related to the modern horsetail. ... Coal (previously referred to as pitcoal or seacoal) is a fossil fuel extracted from the ground by underground mining or open-pit mining (surface mining). ...

The superficially similar flowering plant, Mare's tail (Hippuris vulgaris), unrelated to the genus Equisetum, is occasionally misidentified and misnamed as a horsetail. Classes Magnoliopsida- Dicots Liliopsida- Monocots The flowering plants (also called angiosperms) are a major group of land plants. ... Species Hippuris montana Hippuris tetraphylla Hippuris vulgaris Hippuridaceae is the Mares tail family. ...

Species

• Subgenus Equisetum

Equisetum arvense - Field or Common Horsetail
Equisetum bogotense - Andean Horsetail
Equisetum diffusum - Himalayan Horsetail
Equisetum fluviatile - Water Horsetail
Equisetum palustre - Marsh Horsetail
Equisetum pratense - Shade Horsetail
Equisetum sylvaticum - Wood Horsetail
Equisetum telmateia - Great Horsetail Binomial name Equisetum fluviatile L. The Water Horsetail (Equisetum fluviatile), also known as the Swamp Horsetail, is a perennial horsetail that commonly grows in dense colonies along freshwater shorelines or in shallow water, growing in ponds, swamps, ditches, and other sluggish or still waters with mud bottoms. ... Binomial name Equisetum sylvaticum L. The Wood Horsetail (Equisetum sylvaticum) is a horsetail (family Equisetaceae) native to the Northern Hemisphere, occurring in North America, Eurasia, and Asia. ...

• Subgenus Hippochaete

Equisetum giganteum - Giant Horsetail
Equisetum myriochaetum - Mexican Giant Horsetail
Equisetum hyemale - Rough Horsetail
Equisetum laevigatum - Smooth Horsetail
Equisetum ramosissimum - Branched Horsetail
Equisetum scirpoides - Dwarf Horsetail
Equisetum variegatum - Variegated Horsetail Equisetum giganteum L. of Equisetaceae family is a fern typically growing 1. ...

References

• Pryer, Kathleen M., Eric Schuettpelz, Paul G. Wolf, Harald Schneider, Alan R. Smith and Raymond Cranfill. 2004. Phylogeny and evolution of ferns (monilophytes) with a focus on the early leptosporangiate divergences. American Journal of Botany 91:1582-1598 (online abstract here).

External links

• UK National Collection - includes a taxonomic list of all known species and hybrids
• The Wonderful World of Equisetum
• Giant horsetails
• Equisetum hyemale

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Category:Equisetaceae