Pteridium aquilinum (bracken)
- Summary of Invasiveness
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Plant Type
- Distribution Table
- History of Introduction and Spread
- Risk of Introduction
- Habitat List
- Hosts/Species Affected
- Biology and Ecology
- Latitude/Altitude Ranges
- Air Temperature
- Rainfall Regime
- Soil Tolerances
- Natural enemies
- Notes on Natural Enemies
- Means of Movement and Dispersal
- Impact Summary
- Environmental Impact
- Impact: Biodiversity
- Social Impact
- Risk and Impact Factors
- Uses List
- Similarities to Other Species/Conditions
- Prevention and Control
- Links to Websites
- Distribution Maps
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PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Pteridium aquilinum (L.) Kuhn
Preferred Common Name
Other Scientific Names
- Pteridium esculentum (Forst.) Nakai
- Pteridium revolutum (Bl.) Nakai
- Pteris aquilina L.
International Common Names
- English: bracken fern
- Spanish: felguera; helecho comun; helecho hembra; palma (Mexico); pecho de caballo; petalillo
- French: fougère
- Portuguese: feto-ordinario
Local Common Names
- Belgium: adelaarsvaren
- Brazil: feio; feto; pluma grande; samambaia
- Canada: American bracken; American brake; brake; eastern bracken; fouère à l'aigle; fougère d'aigle; fougère impériale; fougère-aigle commune; fougère-aigle de l'est; fougère-aigle de l'ouest; fougère-paille; grande fougère; grande fougère de l'ouest; hog brake; pasture brake; polypode à feuilles recourbée; ptéride aigle; ptéride aigle-impériale; ptéridie aigle-impériale; ptéridie d'aigle; ptéridie latiuscule; ptéridium à ailes d'aigles; pteridium aquilin; ptéridium des aigles; ptéridium large; ptéris aigle-impériale; western bracken
- Denmark: ornebregne
- El Salvador: crespillo
- Fiji: mata; qato; qato cuva; quato
- Finland: sananjalka
- Germany: Farnkraut
- Guinea: gbologola; gbowolowoulou; kossé; koumto; sankan
- Indonesia: pakis jemblung
- Italy: felse aquilina
- Japan: warabi
- Korea, Republic of: kosari
- Madagascar: apanga
- Netherlands: adelaarsvaren, gewoone
- Norway: einstape
- Philippines: pakong buwaya
- Puerto Rico: felpa
- South Africa: adelaarsvaring; brake; eagle fern; hog-pasture brake; hombewe; muvanguluvha; pasture brake; ukozani
- Sweden: oernbraeken, vanlig
- Thailand: kut kin
- USA: eastern brakenfern; southern bracken; tailed bracken; western brackenfern
- Zambia: luputu
- PTEAQ (Pteridium aquilinum)
- PTERE (Pteridium revolutum)
Summary of InvasivenessTop of page P. aquilinum is a cosmopolitan weed that readily spreads into pasture and marginal areas and is favoured by fire and soil acidity. Its presence reduces land productivity and adversely affects biodiversity. The plant is little affected by animals because of its toxicity. P. aquilinum is difficult to control particularly because of its ability to sprout from an extensive network of underground rhizomes and has large reserves of carbohydrate.
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Pteridophyta
- Class: Pteridopsida
- Family: Dennstaedtiaceae
- Genus: Pteridium
- Species: Pteridium aquilinum
Notes on Taxonomy and NomenclatureTop of page The genus Pteridium (Dennstaedtiaceae) comprises a few relatively stable morphotypes which are at least partially interfertile. Tryon (1941) recognized a single species with two sub-species, containing 12 varieties, and this scheme has been used throughout the world until recent taxonomic advances have made by using both morphometric analysis and DNA fingerprinting. Thomson (2000) reported that morphometric comparisons of frond material grown under standard environmental conditions and DNA fingerprinting by arbitrarily primed PCR were used to assess taxonomic groupings and relationships in the cosmopolitan bracken ferns of 11 of these varieties, excluding var. feei from Central America. This work resolved groupings corresponding to the varieties, var. africanum, var. arachnoideum, var. esculentum, var. latiusculum and var. revolutum from each other. The molecular analysis carried out by Thomson (2000) appeared to elucidate the genetic relationships and some origins of the various varieties studied, concluding that these results were consistent with those from the morphometric analysis, and that the varieties might best be raised in rank to species level. However, apart from some work in Australia in particular, the literature does not reflect the changes suggested by Thomson (2000), and indeed in many instances, such as for publications relating to Africa, the plant is simply referred to as P. aquilinum. Correspondingly, this datasheet employs the all-embracing P. aquilinum concept.
DescriptionTop of page P. aquilinum is a polycarpic geophyte; a perennial fern which reproduces by spores and widely creeping, branching underground stems, sometimes forming colonies. The fronds arise directly from a deep underground rhizome that is much subdivided. The large compound leaves (fronds) are 0.3-1.3 m high, and 15-45 cm long, whereas both fertile and sterile fronds may reach a height of up to 2 m in the UK and can be much smaller under sub-optimal conditions. The leaf stalk, usually mistaken for the stem, actually is attached to the rhizome under the ground. The triangular deciduous leaves turn brown and die after the first autumn frosts in temperate climates, and the new ones arise each spring from the rhizomes. The leaf is divided into numerous segments (leaflets), each of which may be again divided or redivided, with the lowest segments three times compound. The clusters of spore cases densely line the inrolled edges of the underside of the leaves. The sporangium is aggregated into sori on the underside of the frond. Young fronds produce extrafloral nectaries (Grime et al., 1988; Duc et al., 2003).
Plant TypeTop of page Herbaceous
DistributionTop of page
This group of closely related subspecies probably has the largest world distribution of any plant taxa, occurring in much of the temperate and tropical regions on all continents as well as mainly oceanic islands. The extent of the native range is very broad in the general literature and countries in its native range are listed for Africa, Asia, Europe and North America in USDA-ARS (2003). There are very few reports of P. aquilinum as an introduced species. It can become extremely widespread and cover large parts of the landscape, for example, 8% of the area of Scotland, UK. However, there is much regional variation in the recognized types of cover (continuous versus discontinuous) (Birnie et al., 2000). Whether the species is weedy or invasive in each of the countries when known to occur is debatable, and as such has been left as 'unknown' in the Distribution table. It may, however, be considered invasive in at least some of these countries by using any of the definitions, and as such is classified as an invasive species in the Risk and Impacts table.
Distribution TableTop of page
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Reference||Notes|
|Afghanistan||Present||Native||Holm et al., 1979|
|China||Widespread||Native||Flora of China Editorial Committee, 2003|
|-Anhui||Present||Native||Flora of China Editorial Committee, 2003|
|-Fujian||Present||Native||Flora of China Editorial Committee, 2003|
|-Gansu||Present||Native||Flora of China Editorial Committee, 2003|
|-Guangdong||Present||Native||Flora of China Editorial Committee, 2003|
|-Guangxi||Present||Native||Flora of China Editorial Committee, 2003|
|-Guizhou||Present||Native||Flora of China Editorial Committee, 2003|
|-Hainan||Present||Native||Flora of China Editorial Committee, 2003|
|-Hebei||Present||Native||Flora of China Editorial Committee, 2003|
|-Heilongjiang||Present||Native||Flora of China Editorial Committee, 2003|
|-Henan||Present||Native||Flora of China Editorial Committee, 2003|
|-Hong Kong||Present||Native||Flora of China Editorial Committee, 2003|
|-Hubei||Present||Native||Flora of China Editorial Committee, 2003|
|-Hunan||Present||Native||Flora of China Editorial Committee, 2003|
|-Jiangsu||Present||Native||Flora of China Editorial Committee, 2003|
|-Jiangxi||Present||Native||Flora of China Editorial Committee, 2003|
|-Jilin||Present||Native||Flora of China Editorial Committee, 2003|
|-Liaoning||Present||Native||Flora of China Editorial Committee, 2003|
|-Macau||Present||Native||Flora of China Editorial Committee, 2003|
|-Nei Menggu||Present||Native||Flora of China Editorial Committee, 2003|
|-Ningxia||Present||Native||Flora of China Editorial Committee, 2003|
|-Qinghai||Present||Native||Flora of China Editorial Committee, 2003|
|-Shaanxi||Present||Native||Flora of China Editorial Committee, 2003|
|-Shandong||Present||Native||Flora of China Editorial Committee, 2003|
|-Shanghai||Present||Native||Flora of China Editorial Committee, 2003|
|-Shanxi||Present||Native||Flora of China Editorial Committee, 2003|
|-Sichuan||Present||Native||Flora of China Editorial Committee, 2003|
|-Xinjiang||Present||Native||Flora of China Editorial Committee, 2003|
|-Yunnan||Present||Native||Flora of China Editorial Committee, 2003|
|-Zhejiang||Present||Native||Flora of China Editorial Committee, 2003|
|India||Widespread||Native||Holm et al., 1979|
|Indonesia||Present||Native||Holm et al., 1979|
|Iran||Present||Native||Holm et al., 1979|
|Iraq||Present||Native||Holm et al., 1979|
|Israel||Present||Native||Holm et al., 1979|
|Japan||Widespread||Native||Guo et al., 2003|
|Korea, DPR||Present||Native||USDA-ARS, 2003|
|Korea, Republic of||Present||Native||USDA-ARS, 2003|
|Pakistan||Present||Native||Holm et al., 1979|
|Sri Lanka||Present||Native||Holm et al., 1979|
|Taiwan||Present||Native||Flora of China Editorial Committee, 2003|
|Thailand||Present||Native||Holm et al., 1979|
|Turkey||Present||Native||Holm et al., 1979|
|Vietnam||Present||Native||Missouri Botanical Garden, 2003|
|Burundi||Restricted distribution||Native||Hemp, 2002|
|Congo Democratic Republic||Present||Native||Holm et al., 1979|
|Equatorial Guinea||Present||Native||Adams, 1957|
|Ethiopia||Present||Native||Holm et al., 1979|
|Gabon||Present||Native||Missouri Botanical Garden, 2003|
|Ghana||Present||Native||Holm et al., 1979|
|Kenya||Restricted distribution||Native||Hemp, 2002|
|Madagascar||Present||Native||Bloesch et al., 2002|
|Mauritius||Present||Native||Vaughan and Wiehe, 1937|
|Rwanda||Restricted distribution||Native||Hemp, 2002|
|Sao Tome and Principe||Present||Native||Adams, 1957|
|Sierra Leone||Present||Native||Missouri Botanical Garden, 2003|
|South Africa||Widespread||Native||Bromilow, 1995|
|-Canary Islands||Widespread||Native||Tutin and et al, 1964|
|Sudan||Restricted distribution||Native||Jackson, 1956|
|Tanzania||Restricted distribution||Native||Hemp, 2000|
|Zimbabwe||Present||Native||Holm et al., 1979|
|Bermuda||Present||Native||Thomson and Alonso-Amelot, 2002|
|Canada||Present||Present based on regional distribution.|
|-British Columbia||Present||Native||Darbyshire, 2003|
|-New Brunswick||Present||Native||Darbyshire, 2003|
|-Newfoundland and Labrador||Present||Native||Darbyshire, 2003|
|-Nova Scotia||Present||Native||Darbyshire, 2003|
|-Prince Edward Island||Present||Native||Darbyshire, 2003|
|Saint Pierre and Miquelon||Present||Native||Darbyshire, 2003|
|USA||Present||Present based on regional distribution.|
|-New Hampshire||Present||Native||Crane, 1990|
|-New Jersey||Present||Native||Crane, 1990|
|-New Mexico||Present||Native||Crane, 1990|
|-New York||Present||Native||Crane, 1990|
|-North Carolina||Present||Native||Crane, 1990|
|-North Dakota||Present||Native||Crane, 1990|
|-Rhode Island||Present||Native||Crane, 1990|
|-South Carolina||Present||Native||Crane, 1990|
|-South Dakota||Present||Native||Crane, 1990|
|-West Virginia||Present||Native||Crane, 1990|
Central America and Caribbean
|Bahamas||Present||Introduced||Invasive||Kairo et al., 2003|
|Belize||Present||Native||Missouri Botanical Garden, 2003|
|Costa Rica||Present||Native||Thomson and Alonso-Amelot, 2002|
|Cuba||Restricted distribution||Native||Seifriz, 1943|
|El Salvador||Present||Native||Holm et al., 1979|
|Guatemala||Present||Native||Thomson and Alonso-Amelot, 2002|
|Honduras||Present||Native||Thomson and Alonso-Amelot, 2002|
|Jamaica||Present||Introduced||Invasive||Kairo et al., 2003|
|Nicaragua||Present||Native||Missouri Botanical Garden, 2003|
|Panama||Present||Native||Missouri Botanical Garden, 2003|
|Puerto Rico||Present||Native||Missouri Botanical Garden, 2003|
|Trinidad and Tobago||Present||Native||Beard, 1953|
|Argentina||Present||Native||Thomson and Alonso-Amelot, 2002|
|Bolivia||Present||Native||Thomson and Alonso-Amelot, 2002|
|-Espirito Santo||Present||Native||Lorenzi, 1982|
|-Fernando de Noronha||Present||Native||Lorenzi, 1982|
|-Mato Grosso||Present||Native||Lorenzi, 1982|
|-Minas Gerais||Present||Native||Lorenzi, 1982|
|-Rio de Janeiro||Present||Native||Lorenzi, 1982|
|-Rio Grande do Norte||Present||Native||Lorenzi, 1982|
|-Rio Grande do Sul||Present||Native||Lorenzi, 1982|
|-Santa Catarina||Present||Native||Lorenzi, 1982|
|-Sao Paulo||Present||Native||Lorenzi, 1982|
|Colombia||Present||Native||Thomson and Alonso-Amelot, 2002|
|Ecuador||Present||Native||Thomson and Alonso-Amelot, 2002|
|French Guiana||Present||Native||Thomson and Alonso-Amelot, 2002|
|Guyana||Present||Native||Thomson and Alonso-Amelot, 2002|
|Paraguay||Present||Native||Thomson and Alonso-Amelot, 2002|
|Peru||Present||Native||Thomson and Alonso-Amelot, 2002|
|Suriname||Present||Native||Thomson and Alonso-Amelot, 2002|
|Uruguay||Present||Native||Thomson and Alonso-Amelot, 2002|
|Venezuela||Present||Native||Thomson and Alonso-Amelot, 2002|
|Albania||Widespread||Native||Tutin and et al, 1964|
|Andorra||Widespread||Native||Tutin and et al, 1964|
|Austria||Widespread||Native||Tutin and et al, 1964|
|Belarus||Widespread||Native||Tutin and et al, 1964|
|Belgium||Widespread||Native||Tutin and et al, 1964|
|Bosnia-Hercegovina||Widespread||Native||Tutin and et al, 1964|
|Bulgaria||Widespread||Native||Tutin and et al, 1964|
|Croatia||Widespread||Native||Tutin and et al, 1964|
|Cyprus||Widespread||Native||Tutin and et al, 1964|
|Czech Republic||Widespread||Native||Tutin and et al, 1964|
|Denmark||Widespread||Native||Tutin and et al, 1964|
|Estonia||Widespread||Native||Tutin and et al, 1964|
|Finland||Widespread||Native||Tutin and et al, 1964|
|France||Widespread||Native||Tutin and et al, 1964|
|-Corsica||Widespread||Native||Tutin and et al, 1964|
|Germany||Widespread||Native||Tutin and et al, 1964|
|Gibraltar||Widespread||Native||Tutin and et al, 1964|
|Greece||Widespread||Native||Tutin and et al, 1964|
|Hungary||Widespread||Native||Tutin and et al, 1964|
|Ireland||Widespread||Native||Tutin and et al, 1964|
|Italy||Widespread||Native||Tutin and et al, 1964|
|Latvia||Widespread||Native||Tutin and et al, 1964|
|Liechtenstein||Widespread||Native||Tutin and et al, 1964|
|Lithuania||Widespread||Native||Tutin and et al, 1964|
|Luxembourg||Widespread||Native||Tutin and et al, 1964|
|Macedonia||Widespread||Native||Tutin and et al, 1964|
|Malta||Widespread||Native||Tutin and et al, 1964|
|Moldova||Widespread||Native||Tutin and et al, 1964|
|Monaco||Widespread||Native||Tutin and et al, 1964|
|Netherlands||Widespread||Native||Tutin and et al, 1964|
|Norway||Widespread||Native||Tutin and et al, 1964|
|Poland||Widespread||Native||Tutin and et al, 1964|
|Portugal||Widespread||Native||Tutin and et al, 1964|
|-Azores||Widespread||Native||Tutin and et al, 1964|
|-Madeira||Widespread||Native||Tutin and et al, 1964|
|Romania||Widespread||Native||Tutin and et al, 1964|
|Russian Federation||Present||Present based on regional distribution.|
|-Central Russia||Widespread||Native||Tutin and et al, 1964|
|-Eastern Siberia||Widespread||Native||Tutin and et al, 1964|
|-Northern Russia||Widespread||Native||Tutin and et al, 1964|
|-Russian Far East||Widespread||Native||Tutin and et al, 1964|
|-Southern Russia||Widespread||Native||Tutin and et al, 1964|
|-Western Siberia||Widespread||Native||Tutin and et al, 1964|
|San Marino||Widespread||Native||Tutin and et al, 1964|
|Serbia||Widespread||Native||Tutin and et al, 1964|
|Slovakia||Widespread||Native||Tutin and et al, 1964|
|Slovenia||Widespread||Native||Tutin and et al, 1964|
|Spain||Widespread||Native||Tutin and et al, 1964|
|-Balearic Islands||Widespread||Native||Tutin and et al, 1964|
|Sweden||Widespread||Native||Tutin and et al, 1964|
|Switzerland||Widespread||Native||Tutin and et al, 1964|
|UK||Widespread||Native||Tutin and et al, 1964|
|-Channel Islands||Widespread||Native||Tutin and et al, 1964|
|Ukraine||Widespread||Native||Tutin and et al, 1964|
|Yugoslavia (former)||Widespread||Native||Tutin and et al, 1964|
|Australia||Present||Present based on regional distribution.|
|New Zealand||Widespread||Native||Holm et al., 1979|
|Norfolk Island||Restricted distribution||Native||Braggins, 1996|
History of Introduction and SpreadTop of page Little is known about the potential dispersal of the species but it is unlikely to have been intentionally moved by humans and if it has it would have been restricted to a few regions of the world. It is likely that some movement of the plant (rhizome) has happened via movement of soil. The only report of the species being exotic is from Jamaica and the Bahamas, and it would appear that it is only invasive in the former location (Kairo et al., 2003).
Risk of IntroductionTop of page P. aquilinum is cosmopolitan in its distribution and there appears to be only a limited risk of further introduction.
HabitatTop of page Species of the genus Pteridium are seriously weedy in marginal land in many parts of the world, such as in the UK where P. aquilinum is particularly a problem in the uplands. In North America, Pteridium spp. occur readily in dry to wet forest margins and openings, peatbogs, logged areas and dry meadows from coastal to sub-alpine zones (Douglas et al., 1991). In the UK, it affects not only rough grasslands but also significantly impacts heather moorland (Birnie et al., 2000) but is also found in woodlands, wastelands, riverbanks and cliffs (Grime et al., 1988). In central Cameroon it is commonly found at the forest savanna boundary and is often associated with the invasive Chromolaena odorata (Youta-Happi, 1998). In much of the tropics, Pteridium spp. is common in some mountain areas and will become more dominant where fire occurs (D'Antonio et al., 2000; Wesche et al., 2000). P. aquilinum is found in a variety of sites in sun to partial shade and on soils that range from deep and rich to hard-packed or sandy. It is one of the first plants to colonize logged or cleared areas though it seldom persists in cultivated areas.
Habitat ListTop of page
|Terrestrial – Managed||Cultivated / agricultural land||Present, no further details||Harmful (pest or invasive)|
|Managed forests, plantations and orchards||Present, no further details||Harmful (pest or invasive)|
|Managed grasslands (grazing systems)||Present, no further details||Harmful (pest or invasive)|
|Disturbed areas||Present, no further details||Harmful (pest or invasive)|
|Rail / roadsides||Present, no further details|
|Terrestrial ‑ Natural / Semi-natural||Natural forests||Present, no further details||Harmful (pest or invasive)|
|Natural grasslands||Present, no further details||Harmful (pest or invasive)|
|Coastal areas||Present, no further details|
Hosts/Species AffectedTop of page P. aquilinum affect grasslands, forestry plantations, and some cultivated areas.
Biology and EcologyTop of page Genetics
The chromosome number of P. aquilinum var. aquilinum is 2n=104 with a nuclear DNA amount of 12.8 pg (Grime et al., 1988). In his taxonomic re-assessment of the genus Thomson (2000) concluded that the DNA evidence suggested that morphotypes in Pteridium were "determined by specific qualitative and quantitative combinations of a limited number of highly conserved, additively assorted, genomic elements". It exhibits polymorphism for cyanogenesis (Grime et al., 1988). Morphological and morphometric analysis by Thomson (2000) elucidated some genetic relationships between varieties, including the distinguishing of an additional grouping of Atlantic Island (Azores, Madeira) and European brackens as an 'aquilinum complex' including var. aquilinum and a number of morphotypes recognised by C.N. Page and others at various taxonomic levels (near atlanticum, fulvum, pinetorum, osmundaceum). Also, he confirmed that var. yarrabense was a tetraploid hybrid (2n=208) of var. esculentum and var. revolutum, that at least those accessions of var. caudatum examined were tetraploid hybrids (2n=208) involving var. arachnoideum as one progenitor, and that the closest relatives of var. decompositum were var. latiusculum and var. revolutum; and provided evidence of close genomic relationships between var. latiusculum, var. pseudocaudatum and var. pubescens in North America. Thomson (2000) suggested that Tryon's varieties africanum, aquilinum, arachnoideum, decompositum, esculentum, latiusculum and revolutum might best be treated as species; pseudocaudatum and pubescens as varieties within latiusculum; yarrabense and caudatum (at least in part) as hybrids. Thomson and Alonso-Amelot (2002) have dealt with the taxonomic status and relationships of Pteridium caudatum in Central and South America. However, this datasheet does not separate the species as described by Thomson (2000) and covers all varieties within the over-arching P. aquilinum.
Physiology and Phenology
In temperate climates, fronds emerge from late spring onwards and persist until the autumn. Spores ripen in August to September and are shed in August to October in the UK. Under experimental conditions half of the spores take 4 days to germinate and germination is to some extent inhibited by darkness, and the prothallus will grow better in unshaded habitats (Grime et al., 1988). In Western Europe the shoots are copper brown during the dormant season and the fronds will be still standing for much of the winter and only gradually break up. The fronds will grow after the winter season whereas in tropical regions this will tend to occur after fires. Wynn et al. (2000) demonstrated significant differences in response to light and temperature regimes between four genotypes grown under experimental conditions. There is much variation in both the total dry mass per unit area (1.8-5.1 kg/m²) and the total rhizome dry mass (0.24-0.42 kg/m²).
Pteridium spp. are to a large extent fire-resistant as the rhizomes send up new shoots after the old ones are burnt. In tropical regions the species is often referred to as a typical postfire successional species (Wesche et al., 2000) and after fire may form so-called 'bracken savannas' (Beard, 1953). However, in Sudan, it is absent from the most fiercely burnt hillsides (Jackson, 1956). In Hawaii, where it is uncommon, it is one of the few seasonal sub-montane native species to increase in burned compared to unburned areas (D'Antonio et al., 2000). Similarly, in much of the temperate zones it is known to be fire-responsive (Cwynar, 1987; Skre et al., 1998). Indigenous peoples such as the Maoris in New Zealand would appear to have been responsible for the increase of the fern through their use of fire (Germann and Holland, 2001).
Up to 30 million spores may be produced by a single frond and spore production tends to be greater in open habitats. Spores are wind-dispersed. Viable spores are often found in abundance within a soil profile, and a buried spore bank is suspected. Spores may remain viable for up to 10 years. Natural regeneration from spores may occur in spring and is mainly restricted to areas of disturbed or burnt ground. Expansion of established clones will be chiefly vegetative (Grime et al., 1988).
Pteridium spp. are commonly found at varying altitudes. In the UK, P. aquilinum is found from sea level to 590 m but is more abundant in the uplands (Grime et al., 1988). In the Imatong Mountains of Sudan its altitudinal range is 1800-2600 m (Jackson, 1956) and up to 3200 m in Colombia (Missouri Botanical Garden, 2003). It prefers acid soil, tolerating soil pH of 3.0-7.6. However, in the UK, it is most frequent and abundant below pH 4.5 and particularly on deep soils. It is found on a range of shaded and unshaded habitats but grows best on productive brown-earths and more open habitats. Young shoots are very sensitive to frost and trampling by large mammals (Grime et al., 1988).
The roots bear vesicular-arbuscular mycorrhiza (Grime et al., 1988). The extrafloral nectaries of young fronds provide food for ants and these may rid the plant of insect predators (Tempel, 1983; Grime et al., 1988). In Western Europe herbivory by large mammals such as deer, results in a reduction in many palatable species and with the expansion of P. aquilinum (Lameire et al., 2000; Kirby, 2001). In the UK, vegetational change from arable land to woodland over 100 years resulted in the unexpectedly disappearance of P. aquilinum once the woodland had become established (Harmer et al., 2001). Often there is little vegetation under the canopy of P. aquilinum, just a carpet of its litter. The plant is also considered to be allelopathic (Grime et al., 1988).
Latitude/Altitude RangesTop of page
|Latitude North (°N)||Latitude South (°S)||Altitude Lower (m)||Altitude Upper (m)|
Air TemperatureTop of page
|Parameter||Lower limit||Upper limit|
|Mean annual temperature (ºC)||9||29|
RainfallTop of page
|Parameter||Lower limit||Upper limit||Description|
|Dry season duration||0||6||number of consecutive months with <40 mm rainfall|
Rainfall RegimeTop of page Bimodal
Soil TolerancesTop of page
- very acid
Special soil tolerances
Natural enemiesTop of page
|Natural enemy||Type||Life stages||Specificity||References||Biological control in||Biological control on|
Notes on Natural EnemiesTop of page Although P. aquilinum is considered to be heavily defended from mammalian and insect predators (Grime et al., 1988), many insects have been recorded on the plant (Crane, 1990) though their effects on growth and survival are not known. A number of insects attacking P. aquilinum were identified from the UK (Lawton, 1976) New Mexico, USA (Lawton, 1982) and Brazil (Martins et al., 1995), some of which were investigated as potential biological control agents. Lawson (1976) lists 40 species of arthropods feeding on P. aquilinum in the UK and notes seasonal changes in relation to the plant's defense mechanisms against herbivory.
Means of Movement and DispersalTop of page Spores are principally wind-dispersed. There is no known natural dispersal of spores. Soil containing live rhizomes either attached to agricultural machinery or disposed of in landfill sites are possible means of introduction to new areas though no instances have been documented. Intentional introduction is a most unlikely pathway in view of the limited uses and no positive traits of this species.
Impact SummaryTop of page
|Fisheries / aquaculture||None|
ImpactTop of page When mature and tough, fronds of P. aquilinum are poisonous to horses and cattle. The rhizomes are five times more toxic than the leaves, but are seldom eaten. Sheep have been poisoned experimentally, but natural poisoning is not common. The poison is cumulative over about 1 month for horses and 1-4 months for cattle before symptoms appear. Horses are usually poisoned by eating large amounts of contaminated hay, containing over 20% P. aquilinum, whereas cattle are poisoned by consuming an amount of green or dried leaves approximately equal to the animal's weight. In the UK, it is a weed of grasslands and forestry and is increasing in the uplands and is difficult to eradicate (Grime et al., 1988). It affects farmers in many parts of the world, with lost opportunity costs associated with the invasion of productive grazing land, veterinary costs associated with poisoning and tumours, ticks and associated disease problems and direct bracken control costs. In forestry plantations, control is often required during the establishment phase (Pakeman et al., 2003).
Environmental ImpactTop of page In terms of conservation, P. aquilinum often has little biodiversity interest and in Britain it has generally replaced habitats of greater importance (Pakeman et al., 2003).
Impact: BiodiversityTop of page In Europe there is some evidence that a decrease in species richness over time may be due to competitive exclusion by P. aquilinum (Lameire et al., 2000).
Social ImpactTop of page The plant is toxic to livestock and humans (Grime et al., 1988; Crane, 1990). The impact on human health is difficult to quantify, but Pakeman et al. (2003) consider that it could be locally important. There is unproven speculation that drinking water taken from catchments that are predominantly covered with P. aquilinum may contain carcinogens or other toxins that are harmful to human health.
Risk and Impact FactorsTop of page Invasiveness
- Invasive in its native range
- Proved invasive outside its native range
- Highly adaptable to different environments
- Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
- Has high reproductive potential
- Has propagules that can remain viable for more than one year
- Damaged ecosystem services
- Ecosystem change/ habitat alteration
- Negatively impacts agriculture
- Negatively impacts human health
- Negatively impacts animal health
- Negatively impacts tourism
- Reduced amenity values
- Reduced native biodiversity
- Competition - monopolizing resources
- Difficult/costly to control
UsesTop of page In New Zealand, the Maori ate the starchy, below-ground parts of the fern and used fire as an aid for hunting and to promote regrowth of this edible resource (Germann and Holland, 2001). Faust (2002) has reviewed the ethnobotany of the species in the Yucatan Peninsula. In early spring, the young unrolled leaves and tender leaf stalks may also be cooked as a vegetable, and are consumed in Thailand and Japan, even though they contain carcinogens (USDA-ARS, 2003). In the UK, it used to have some economic importance as a source of fuel, thatch, bedding, compost, food and potash (Grime et al., 1988). It is occasionally used for sheep bedding in Wales to this day, though in small amounts to avoid poisoning of stock from consumption, due to beliefs concerning its possible ethnoveterinary effects. Potential uses of P. aquilinum in organic agriculture in the UK are being considered (Donnelly et al., 2002) and it is being promoted as a component of peat-free growing media (Pitman and Webber, 1998). There are numerous uses in folkloric medicine (USDA-ARS, 2003).
Uses ListTop of page
Human food and beverage
- Poisonous to mammals
Similarities to Other Species/ConditionsTop of page Whereas the genus Pteridium is readily distinguished from other fern taxa, separation of the various species/subspecies within the genus is difficult (Thomson, 2000).
Prevention and ControlTop of page Cultural Control
The plant is susceptible to damage by the trampling of fronds by large mammals, but this does little to control the plant. Frequent liming (to increase soil pH) and fertilizer applications used in upland grassland improvement also have the additional benefit of reducing infestations of P. aquilinum, as it is a plant of infertile acid soils. Reseeding with preferable forage grasses or herbaceous species also appears to reduce the cover of P. aquilinum, such as has been achieved with Festuca rubra and Vicia cassubica in Bulgaria (Petrov and Marrs, 2000).
Duc et al. (2000) have considered the mechanical control of P. aquilinum in the UK by cutting it once or twice a year, which reduced the total dry mass per unit area by approximately 60% after 5 years. Any mechanical treatment must be conducted over a number of years if it is to have any noticeable effect (Marrs et al., 2000). Also timing of the cuts is very important, for example the optimal time is in the autumn, before P. aquilinum has transferred its nutrient reserves from the above-ground parts back down to the rhizomes for the dormant winter period.
Control by herbicide is generally difficult. Asulam has been the main chemical used in control programmes in the UK since the early 1970s, primarily because it is licensed for aerial spraying. Of other chemicals that have been tried, only glyphosate has been used in some situations where P. aquilinum is one of a number of weeds to be controlled. In recent years, aerial spraying using helicopters has been carried out on around 5000-8000 ha per year. However, only about 25% of sites sprayed with asulam show long-term suppression of bracken whilst the remaining sites normally revert back to complete P. aquilinum cover within 5-10 years. Therefore appropriate follow-up treatment is essential, such as knapsack or vehicle-based spot spraying of missed areas or regenerating fronds (Pakeman et al., 2003). In Bulgaria, glyphosate applied to a permanent meadow infested with P. aquilinum reduced the infestation but it rapidly recovered where no follow-up operations were carried out, and was more successful when carried out in combination with a follow-up weed wiping application of glyphosate (Petrov and Marrs, 2000). Metsulfuronmethyl and glyphosate-trimesium are recommended for use on P. esculentum in Tasmania (Anon., 2003).
In the UK, where P. aquilinum is a major weed of pasture in particular, studies on biological control were initiated in the 1970s. Lawson (1976) identified 40 arthropod species feeding on P. aquilinum, but noted their inability to prevent spread of infestations owing to the impact of native natural enemies of the arthropods. Lawton (1988) summarized the situation in the UK and discussed the requirements for successful biological control agents, emphasising the need for agents of the same subspecies of the weed, comparable climates, and for agents which would be free from attack ny native natural enemies. South Africa appeared to provide the best likelihood of finding such agents, and Lawson (1988) listed arthropods associated with P. aquilinum there, from hitherto unpublished observations. Two defoliating moths, Panotina angularis and Conservula cinisigna and an unidentified eriophyid mite were considered promising. The moths were imported into quarantine in the UK, screened and found to be host specific (Fowler et al., 1989). However, the programme was abandoned because of the costs of field testing and doubts over the wisdom of using biological control to manage a native weed (Cruttwell McFadyen, 1998). Comparative studies on the arthropod fauna of P. aquilinum on other continents; New Mexico, USA (Lawton, 1982) and Brazil (Martins et al., 1995) have also been made.
Duc et al. (2000) reviewed the responses of fronds to control treatments in Great Britain and noted great variability even within a small geographical area. Follow-up application of herbicide several years after the start of a control programme enhanced the efficacy of all treatments. To develop a control strategy in the UK, Duc et al. (2003) stated the following factors must be considered: that rhizome mass differs between sites and in response to control treatments; cutting twice per year is generally most effective; where cutting is impossible, herbicide treatment should be applied. and the weather may affect rhizome mass, with wet years being detrimental. Also a combination of mechanical and chemical methods may be more effective under some conditions. Pakeman et al. (2003) have pointed out that P. aquilinum control has to be seen as part of a much larger land use/management strategy and they suggest a variety of control scenarios and restoration practices.
ReferencesTop of page
Adams CD, 1957. Observations on the fern flora of Fernando Po: I. A description of the vegetation with particular reference to the Pteridophyta. Journal of Ecology, 45:479-494.
Anon., 2003. Bracken (Pteridium esculentum Forst. F.). Service Sheet. Tasmania Department of Primary Industries, Water and the Environment, Hobart. http://www.dpiwe.tas.gov.au/inter.nsf/WebPages/RPIO-4ZW9TH?open.
Beard JS, 1953. The savanna vegetation of northern Tropical America. Ecological Monographs, 23:149-215.
Birnie RV; Miller DR; Horne PL; Leadbeater S; Macdonald A, 2000. The potential distribution and impact of bracken in upland Scotland: an assessment using a GIS-based niche model. Annals of Botany, 85(Sup B):53-62; 31 ref.
Bloesch U; Bosshard A; Schachenmann P; Rabetaliana H; Klötzli F, 2002. Biodiversity of the subalpine forest-grassland ecotone of the Andringitra Massif, Madagascar. In: Körner C, Spehn E, eds. Mountain biodiversity - a global assessment. CRC Press, Boca Raton, 165-175.
Braggins JE, 1996. Report on the conservation status of Norfolk Island Ferns. Report for the Norfolk Island National Park, Environment Australia. http://www.anbg.gov.au/projects/fern/norfolk_cons.html.
Bromilow C, 2001. Problem Plants of South Africa. Pretoria, South Africa: Briza Publications.
Carrière M, 2000. Flore de Guinée: appellations vernaculaires et usages traditionnels de quelques plantes. http://perso.wanadoo.fr/a.i.r.e./guilex.htm.
Crane MF, 1990. Pteridium aquilinum. Fire Effects Information System, [Online]. USDA Forest Service, USA: Rocky Mountain Research Station, Fire Sciences Laboratory.
Cwynar LC, 1987. Fire the forest history of the North Cascade Ranges (USA, Canada). Ecology, 68:791-802.
D'Antonio CM; Tunison JT; Loh RK, 2000. Variation in the impact of exotic grasses on native plant composition in relation to fire across an elevation gradient in Hawaii. Austral Ecology, 25(5):507-522; 57 ref.
Darbyshire SJ, 2003. Inventory of Canadian agricultural weeds. Ottawa, Canada: Agriculture and Agri-Food Canada.
Donnelly E; Robertson J; Robinson D, 2002. Potential and historical uses for bracken (Pteridium aquilinum (L.) Kuhn) in organic agriculture. In: Powell et al. Eds, UK Organic Research 2002: Proceedings of the COR Conference, 26-28 March 2002, Aberystwyth, Wales, UK, 255-256.
Douglas GW; Straley GB; Meidinger D, 1991. The vascular plants of British Columbia Part 3 - Dicotyledons (Primulaceae through Zygophyllaceae) and Pteridophytes. http://www.for.gov.bc.ca/hfd/pubs/Docs/Srs/Srs03/Srs03-3.pdf.
Duc MG le; Pakeman RJ; Marrs RH, 2000. Vegetation development on upland and marginal land treated with herbicide, for bracken (Pteridium aquilinum) control, in Great Britain. Journal of Environmental Management, 58(2):147-160; 43 ref.
Duc MG le; Pakeman RJ; Marrs RH, 2003. Changes in the rhizome system of bracken subjected to long-term experimental treatment. Journal of Applied Ecology, 40:508-522.
Faust K, 2002. Pteridium aquilinum: the ethnobotany of bracken fern and implications for use in the Yucatan Peninsula. Ethnobotany 170, 1-18. http://maya.ucr.edu/pril/ethnobotany/image/Pteridium.pdf.
Flora of China Editorial Committee, 2003. Flora of China Web. Cambridge, Massachusetts, USA: Harvard University Herbaria. http://flora.huh.harvard.edu/china/.
Germann P; Holland P, 2001. Fragmented ecosystems: people and forests in the mountains of Switzerland and New Zealand. Mountain Research and Development, 21:382-391.
Guo Q; Kato M; Ricklefs RE, 2003. Life history, diversity and distribution: a study of Japanese pteridophytes. Ecography, 26:129-138.
Harmer R; Peterken G; Kerr G; Poulton P, 2001. Vegetation changes during 100 years of development of two secondary woodlands on abandoned arable land. Biological Conservation, 101:291-304.
Hemp A, 2002. Ecology of the pteridophytes on the southern slopes of Mt. Kilimanjaro. I. Altitudinal distribution. Plant Ecology, 159:211-239.
Holm LG; Pancho JV; Herberger JP; Plucknett DL, 1979. A Geographical Atlas of World Weeds. New York, USA: Wiley.
Jackson JK, 1956. The vegetation of the Imatong Mountains, Sudan. Journal of Ecology, 44:341-374.
Kairo M; Ali B; Cheesman O; Haysom K; Murphy S, 2003. Invasive species threats in the Caribbean region. Report to the Nature Conservancy. Curepe, Trinidad and Tobago: CAB International, 132 pp. http://www.issg.org/database/species/reference_files/Kairo%20et%20al,%202003.pdf
Kirby KJ, 2001. The impact of deer on the ground flora of British woodland. Forestry, 74:219-229.
Kowal NE, 1966. Shifting cultivation, fire, and pine forest in the Cordillera Central, Luzon, Philippines. Ecological Monographs, 36:389-419.
Lameire S; Hermy M; Honnay O, 2000. Two decades of change in the ground vegetation of a mixed deciduous forest in an agricultural landscape. Journal of Vegetation Science, 11:695-704.
Lawton RM, 1978. A study of the dynamic ecology of Zambian vegetation. Journal of Ecology, 66:175-198.
Lemon PC, 1968. Effects of fire on an African plateau grassland. Ecology, 49:316-322.
Lorenzi H, 1982. Plantas Daninhas do Brasil. Nova Odessa, San Paulo, Brazil: H. Lorenzi.
Missouri Botanical Garden, 2003. VAScular Tropicos database. St. Louis, USA: Missouri Botanical Garden. http://mobot.mobot.org/W3T/Search/vast.html.
Pakeman RJ; Duc MGle; Marrs RH, 2000. Bracken distribution in Great Britain: strategies for its control and the sustainable management of marginal land. Annals of Botany, 85(Sup B):37-46; 2 pp. of ref.
Parham JW, 1958. The Weeds of Fiji. Bulletin Fiji Department of Agriculture, 35. Suava, Fiji: Government Press.
Sekercioglu CH, 2002. Effects of forestry practices on vegetation structure and bird community of Kibale National Park, Uganda. Biological Conservation, 107:229-240.
Skre O; Wielgolaski FE; Moe B, 1998. Biomass and chemical composition of common forest plants in response to fire in western Norway. Journal of Vegetation Science, 9:501-510.
Thomson JA; Alonso-Amelot ME, 2002. Clarification of the taxonomic status and relationships of Pteridium caudatum (Dennstaedtiaceae) in Central and South America. Botanical Journal of the Linnean Society, 140(3):237-248; 31 ref.
Tryon RM, 1941. A revision of the genus Pteridium. Rhodora, 43:1-31,37-67.
USDA-ARS, 2003. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.aspx
Vaughan RE; Wiehe PO, 1937. Studies on the vegetation of the Mauritius. 1. A preliminary survey of the plant communities. Journal of Ecology, 25:289-342.
Wesche K; Miehe G; Kaeppeli M, 2000. The significance of fire for Afroalpine Ericaceous vegetation. Mountain Research and Development, 20:340-347.
Wynn JM; Small JL; Pakeman RJ; Sheffield E, 2000. An assessment of genetic and environmental effects on sporangial development in bracken [Pteridium aquilinum (L.) Kuhn] using a novel quantitative method. Annals of Botany, 85(Sup B):113-115; 10 ref.
Youta Happi, 1998. Arbres contre graminées: la lente invasion de la savane par la forêt au Centre-Cameroun. Thèse de doctorat, Université de Paris-Sorbonne (Paris IV). http://www.bondy.ird.fr/carto/publi/Youta_pdf/These_Youta.pdf.
Distribution MapsTop of page
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