View source for Bracken

{{Taxobox
| color = lightgreen
| name = ''Pteridium aquilinum''
| image = Pteridium aquilinum.jpg
| image_width = 240px
| regnum = [[Plant]]ae
| divisio = [[fern|Pteridophyta]]
| classis = [[Pteridopsida]]
| ordo = [[Pteridales]]
| familia = [[Hypolepidaceae]]
| genus = '''''Pteridium'''''
| subdivision_ranks = Species
| subdivision = 
''Pteridium aquilinum''<br>
''[[Pteridium caudatum]]''<br>
''[[Pteridium esculentum]]<br>
''[[Pteridium latiusculum]]''<br>
and about 6-7 other species
}}
[[image:Adelaarsvaren planten Pteridium aquilinum.jpg|thumb|right|200px|''Pteridium aquilinum'']]
[[image:Tylerfinvold023_bracken_ferns.jpg|thumb|right|200px|]]
''For the Australian cricketer, see [[Nathan Bracken]].''

{{for|the Irish television soap opera|Bracken (TV)}}
'''Brackens''' ('''''Pteridium''''') are a genus of about ten species of large, coarse [[fern]]s, in the family [[Hypolepidaceae]]. The genus has probably the widest distribution of any fern genus in the world, being found on all continents except [[Antarctica]] and in all environments except for hot and cold deserts. Therefore it is considered to have a [[cosmopolitan distribution]]. In the past, the genus was commonly treated as having only one species, ''Pteridium aquilinum'', but the recent trend is to subdivide it into several species.

[[Evolution]]arily, bracken may be considered to be one of the most successful ferns. The plant sends up large, triangular fronds from a wide-creeping underground rootstock, and may form dense thickets. This rootstock may travel a metre or more underground between fronds. The fronds may grow up to 2.5 m (8 feet) long or longer with support, but typically are in the range of 0.6-2 m (2-6 feet) high. In cold environments bracken is winter-[[deciduous]], and, as it requires well-drained [[soil]], is generally found growing on the sides of hills.

Brackens are used as food plants by the [[larva]]e of some [[Lepidoptera]] species including [[Dot Moth]], [[Phymatopus|Gold Swift]], [[Pharmacis|Map-winged Swift]], [[Orange Swift]] and [[Small Angle Shades]].

'''''Pteridium aquilinum''''' ('''Bracken''' or '''Common Bracken''') is the most common  species   with a [[cosmopolitan distribution]], occurring in temperate and subtropical regions throughout much of the world, including most of [[Europe]], [[Asia]], and [[North America]] in the [[Northern Hemisphere]], and [[Australia]], [[New Zealand]] and northern [[South America]] in the [[Southern Hemisphere]]. It is a prolific and abundant plant in the highlands of [[British Isles]]. It causes such a problem of invading pastureland that at one time the [[United Kingdom|British]] government had an eradication program. Special filters have even been used on some British water supplies to filter out the bracken [[spore]]s.

It is a [[herbaceous]] [[perennial plant]], deciduous in winter. The [[frond]]s are produced singly from an underground [[rhizome]], and grow to 1-3 m tall; the main stem is up to 1 cm diameter at the base.

The plant is a known [[carcinogen]] to animals such as mice, and communities (mainly in [[Japan]] and [[Korea]]) where the young stems are used as a [[vegetable]] have some of the highest [[stomach cancer]] rates in the world [http://www.pubmedcentral.gov/articlerender.fcgi?artid=1177200]. The [[spore]]s have also been implicated as a carcinogen.

The word bracken is of [[Old Norse]] origin, related to the Swedish word ''bräken'', meaning fern.

==Uses==
[[Image:Curled bracken fronds.JPG|thumb|left|Young bracken fronds, curled]]
Bracken [[fiddlehead]]s (the immature, tightly curled emerging fronds) have been considered edible by many cultures throughout history, and are still commonly used today as a foodstuff. Bracken fiddleheads are either consumed fresh (and cooked) or preserved by salting, pickling, or sun drying.  In Korea, where they are called ''gosari namul'', they are a typical ingredient in the mixed rice dish called ''[[bibimbap]]''.

Both [[frond]]s and [[rhizome]]s have been used to brew [[beer]], and the rhizome [[starch]] has been used as a substitute for [[arrowroot]]. Bread can be made out of dried and powered rhizomes alone or with other [[flour]]. [[Indigenous peoples of the Americas|American Indians]] cooked the rhizomes, then peeled and ate them or pounded the starchy fiber into flour. In [[Japan]], starch from the rhizomes used to be used to make confections.

The [[Māori]] of [[New Zealand]] used the rhizomes of ''P. esculentum'' (''aruhe'') as a staple food, especially for exploring or hunting groups away from permanent settlements; much of the widespread distribution of this species in present-day New Zealand is in fact a consequence of prehistoric deforestation and subsequent tending of ''aruhe'' stands on rich soils (which produced the best rhizomes). The rhizomes were air-dried so that they could be stored and became lighter; for consumption, they were briefly heated and then softened with a ''patu aruhe'' (rhizome pounder); the starch could then be sucked from the fibers by each diner, or collected if it were to be prepared for a larger feast. ''Patu aruhe'' were significant items and several distinct styles were developed (McGlone ''et al.'' 2005).

Bracken has also been used as a form of [[herb]]al remedy. Powdered rhizome has been  considered particularly effective against [[Parasite|parasitic worm]]s. American Indians ate raw rhizomes as a remedy for [[bronchitis]].  

Bracken has been shown to be [[carcinogen]]ic and is thought to be an important cause of the high incidence of [[stomach cancer]] in Japan, where it is eaten as a vegetable. It is currently under investigation as a possible source of new [[insecticide]]s.

Besides causing cancer, uncooked bracken contains the [[enzyme]] [[thiaminase]], which breaks down [[thiamine]]. Thus, eating excessive quantities of bracken can also cause [[beriberi]], especially in creatures with simple-stomachs. [[Ruminant]]s are less vulnerable because they synthesize thiamine.

== References ==
* McGlone, Matt S. ''et al.'' (2005): An ecological and historical review of bracken (''Pteridium esculentum'') in New Zealand, and its cultural significance. ''[[New Zealand Journal of Ecology]]'' '''28''':165-184 [http://www.nzes.org.nz/nzje/new_issues/NZJEcol29_2_165.pdf Free fulltext online]<!-- You might want to periodically check the link, because it has been announced that the fulltext will soon be closed except for subscribers. Change to abstract when this becomes the case. -->
* [http://homepages.caverock.net.nz/~bj/fern/pteridium.htm World fern species list - Pteridium]
*[http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?312948 Germplasm Resources Information Network: ''Pteridium aquilinum'']
*[http://rbg-web2.rbge.org.uk/cgi-bin/nph-readbtree.pl/feout?FAMILY_XREF=&GENUS_XREF=Pteridium&SPECIES_XREF=&TAXON_NAME_XREF=&RANK= Flora Europaea: ''Pteridium aquilinum'']
*[http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200003325 Flora of North America: ''Pteridium aquilinum'']

== External links ==
* [http://homepages.caverock.net.nz/~bj/fern/pteridium.htm World fern species list - Pteridium]
* [http://www.rook.org/earl/bwca/nature/ferns/pteridiumaqui.html Independent page devoted to bracken (uses older classification scheme)]

==See also==
*[[Bibimbap]]

{{commons|Pteridium aquilinum}}

[[Category:Pteridophyta]]
[[Category:Plants poisonous to equines]]