Envoy at 19:04, 30 October 2007

2007-10-30T19:04:01Z

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{{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]
* [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]]

Bracken - Revision history

Envoy at 19:04, 30 October 2007