Bracken 66560 224752237 2008-07-10T07:33:22Z 4.255.34.91 added bit about allelopathy in bracken {{Taxobox | name = ''Pteridium aquilinum'' | image = Pteridium_aquilinum_nf.jpg | image_width = 240px | regnum = [[Plant]]ae | divisio = [[fern|Pteridophyta]] | classis = [[Pteridopsida]] | ordo = [[Pteridales]] | familia = [[Dennstaedtiaceae]] | 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|Fronds of the bracken fern]] {{otheruses}} '''Brackens''' ('''''Pteridium''''') are a genus of about ten species of large, coarse [[fern]]s, in the family [[Dennstaedtiaceae]]. 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]]. 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 [[carcinogenic]] to animals such as mice, rats and cattle when ingested. Young stems are used as a [[vegetable]] in [[Japan]], leading some reasearchers to suggest a link between consumption and higher [[stomach cancer]] rates.<ref>[http://www.pubmedcentral.gov/articlerender.fcgi?artid=1177200 The possible human hazard of the naturally occurring bracken carcinogen]</ref> The [[spore]]s have also been implicated as a carcinogen. Danish scientist Lars Holm Rasmussen released a study in 2004 showing that the carcinogenic compound in bracken, [[ptaquiloside]] or PTQ, can leach from the plant into the water supply, which may explain an increase in the incidence of gastric and oesophageal cancers in bracken-rich areas.<ref>[http://www.guardian.co.uk/life/feature/story/0,,1299844,00.html Guardian newspaper article on ptaquiloside from bracken entering water supplies]</ref> In cattle, bracken poisoning can occur in both an acute and chronic form, acute poisoning being the most common. In pigs and horses bracken poisoning induces vitamin B deficiency<ref>Auld, RA & RW Medd, "Weeds", Inkata Press, Sydney, 1992</ref>. Poisoning usually occurs when there is a shortage of available grasses as in drought or snowfalls. [[Allelopathy]]: Bracken fern is known to produce and release allelopathic chemicals, which is an important factor in its ability to dominate other vegetation, particularly in regrowth after fire. Herb and tree seedling growth may be inhibited even after bracken fern is removed, apparently because active plant toxins remain in the soil. The word bracken is of [[Old Norse]] origin, related to the Swedish word ''bräken'', meaning fern. ==Distribution== '''''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 [[Great Britain]]. 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.{{fact|date=March 2008}} ==Uses== [[Image:Curled bracken fronds.JPG|thumb|right|200px|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'' (고사리 나물), 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]]. In East Asia, ''Pteridium aquilinum'' (fernbrake or bracken [[fiddlehead]]s) is eaten as a vegetable, called ''warabi'' (蕨 / わらび) in Japan, ''gosari'' (고사리) in Korea, and ''juécài'' (蕨菜) in China and Taiwan. In Korea, a typical ''[[banchan]]'' (small side dish) is ''gosari-namul'' (고사리나물) that consists of prepared fernbrake that has been sauteed. It is a component of the popular dish ''[[bibimbap]]''. Bracken has been shown to be [[carcinogen]]ic in some animals and is thought to be an important cause of the high incidence of [[stomach cancer]] in Japan. It is currently under investigation as a possible source of new [[insecticide]]s. Uncooked bracken contains the [[enzyme]] [[thiaminase]], which breaks down [[thiamine]]. Eating excessive quantities of bracken can cause [[beriberi]], especially in creatures with simple-stomachs. [[Ruminant]]s are less vulnerable because they synthesize thiamine. ==See also== * [[Bibimbap]] * [[List of plants poisonous to equines]] == References == * [http://www.blackwell-synergy.com/doi/pdf/10.1111/j.1365-2745.2006.01177.x Marrs, R. H. & A. S. Watt (2006) Biological Flora of the British Isles 245: Pteridium aquilinum (L.) Kuhn. Journal of Ecology, 94: 1272-1321.] * 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.newzealandecology.org/nzje/free_issues/NZJEcol29_2_165.pdf]<!-- 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''] <references/> == External links == {{commons|Pteridium aquilinum}} * [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)] * [http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=11945131&query_hl=4&itool=pubmed_docsum Link to a study on the links between cancer and bracken.] *{{eol|16480171|Pteridium aquilinum}} [[Category:Pteridophyta]] [[de:Adlerfarne]] [[es:Pteridium]] [[fr:Pteridium]] [[pl:Orlica (roślina)]] [[fi:Sananjalka]] [[it:Pteridium aquilinum]] [[nl:Adelaarsvaren]] [[sv:Örnbräken]]