''Equisetum pratense'', commonly known as meadow horsetail, shade horsetail or shady horsetail, is a widespread horsetail (

Equisetophyta Equisetidae is one of the four class (biology), subclasses of fern, Polypodiopsida (ferns), a group of vascular plants with a fossil record going back to the Devonian. They are commonly known as horsetails. They typically grow in wet areas, with ...

) fern. Shade horsetail can be commonly found in forests with tall trees or very thick foliage that can provide shade and tends to grow closer and thicker around streams, ponds and rivers. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

'' pratense'' is

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

, meaning pasture or meadow dwelling.

Description

''Equisetum pratense'' has whitish-green and slender sterile stems that grow tall, with 8 to 20 ridges that bear three rows of flat

spinule Spinules are small spines or thorns (vertebral columns) that are part of biological and manmade structures. The word originates from the Latin word and is often used in botany and zoology. The presence or absence of spinules, and their shape, can ...

s. The centrum is approximately one sixth of the diameter of the stem. The pale sheaths bear slender brown teeth with white margins. Cones mature in late spring.

Habitat

''Equisetum pratense'' occurs in

alluvial Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluv ...

woods, thickets, mossy glades, and

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an adje ...

meadows. It is a common pioneer species, commonly growing where instability or water erosion leaves an often open ground surface or where sandy

alluvium Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluv ...

accumulates beside streams. Where vegetation is more abundant, the fern occurs only as sparse and diminutive shoots, as the fern is succumbing to

competition Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indivi ...

in a later seral community. The plant is widespread, occurring from

Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...

and northern Britain and

Northern Ireland Northern Ireland ( ga, Tuaisceart Éireann ; sco, label= Ulster-Scots, Norlin Airlann) is a part of the United Kingdom, situated in the north-east of the island of Ireland, that is variously described as a country, province or region. Nort ...

through northern and central

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

as far south as the

Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Sw ...

. It grows across most of northern

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

and through northern parts of

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

from

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

Labrador , nickname = "The Big Land" , etymology = , subdivision_type = Country , subdivision_name = Canada , subdivision_type1 = Province , subdivision_name1 ...

Toxicity

''Equisetum pratense'' contains the enzyme

thiaminase Thiaminase is an enzyme that metabolizes or breaks down thiamine into two molecular parts. It is an antinutrient when consumed. The old name was "aneurinase". There are two types: * Thiamine pyridinylase, Thiaminase I (, ) * Aminopyrimidine ami ...

which destroys

thiamine Thiamine, also known as thiamin and vitamin B1, is a vitamin, an essential micronutrient, that cannot be made in the body. It is found in food and commercially synthesized to be a dietary supplement or medication. Phosphorylated forms of thi ...

(vitamin B1). In sufficient quantity it is therefore toxic.

References

{{Taxonbar, from=Q1123127 pratense Plants described in 1784 Taxa named by Jakob Friedrich Ehrhart