Epilobium ciliatum (northern willowherb)
- Summary of Invasiveness
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Plant Type
- Distribution Table
- History of Introduction and Spread
- Risk of Introduction
- Habitat List
- Biology and Ecology
- Means of Movement and Dispersal
- Pathway Causes
- Pathway Vectors
- Impact Summary
- Economic Impact
- Environmental Impact
- Risk and Impact Factors
- Uses List
- Similarities to Other Species/Conditions
- Prevention and Control
- Links to Websites
- Distribution Maps
Don't need the entire report?
Generate a print friendly version containing only the sections you need.Generate report
PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Epilobium ciliatum Raf.
Preferred Common Name
- northern willowherb
Other Scientific Names
- Chamaenerion dominii Nábelek
- Epilobium aconcaguinum Phil.
- Epilobium adenocaulon Hausskn.
- Epilobium adenocladon Rydb.
- Epilobium affine Maxim.
- Epilobium alaskae H.Lév.
- Epilobium cunninghamii Hausskn.
- Epilobium fendleri Hausskn.
- Epilobium parishii Trel.
- Epilobium perplexans (Trel.) Trel. ex A.Nelson
- Epilobium praecox Suksd.
- Epilobium pseudolineare Hausskn.
- Epilobium punctatum H.Lév.
- Epilobium rubescens Rydb.
- Epilobium santa-cruzense Dusén
- Epilobium ursinum C.S.P.Parish ex Trel.
- Epilobium valdiviense Hausskn.
International Common Names
- English: american willowherb; fringed willowherb; glandular willowherb; hairy willowherb; hairy willowweed
- Spanish: epibolio ciliado
- French: epilobe cilié
Local Common Names
- Czech Republic: vrbovka zl znat
- Denmark: hvid dueurt; kirtel-dueurt
- Estonia: metspajulill; punakas pajulill
- Finland: amerikanhorsma; vaalea-amerikanhorsma
- Germany: Bewimpertes Weidenroschen; Drüsiges Weidenröschen
- Italy: garofanino ciliato
- Latvia: laukuotastiebe ozkaroze
- Lithuania: dziedzerstublaja kazroze
- Netherlands: gewimperde basterdwederik
- Poland: wierzbownica gruczolowata
- Sweden: amerikansk dunört
Summary of InvasivenessTop of page
E. ciliatum is a dicot perennial herb that is native to much of North America, southern South America and East Asia. It has been accidentally introduced into Europe, Australia and New Zealand. The distribution of this species is increasing as it rapidly spreads over Britain and many other European countries. It produces copious wind-borne seed and can, under favourable conditions, complete its life cycle from seed to seed in as little as nine to ten weeks. E. ciliatum has been described as an aggressive species and can become a noxious weed, particularly in agricultural areas. Even in its native range in North America it has proved to be a problem in agricultural land, in orchards and vineyards and in container plants in nurseries. Due to its rapid growth E. ciliatum can outcompete and displace native plant species. It is also possible for it to hybridize with native Epilobium species. Control of E. ciliatum is difficult to achieve due to herbicide resistance and tolerance.
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Spermatophyta
- Subphylum: Angiospermae
- Class: Dicotyledonae
- Order: Myrtales
- Family: Onagraceae
- Genus: Epilobium
- Species: Epilobium ciliatum
Notes on Taxonomy and NomenclatureTop of page
The genus Epilobium contains around 165 species found in temperate zones, the majority from West North America and also on arctic and tropical mountains (Mabberley, 1997). A total of 79 synonyms of this species are listed on The Plant list (2013).
Stace (2010), in his entry for E. ciliatum, points out that some taxonomists claim that the species E. adenocaulon ‘is distinct, but this name seems predated by E. watsonii Barbey’. According to ITIS (2014)E. adenocaulon is an early synonym for E. ciliatum subsp. ciliatum and E. watsonii [E. ciliatum subsp. watsonii] is a recognized subspecies of E. ciliatum.
ITIS (2014) list three subspecies of E. ciliatum. These include; E. ciliatum subsp. ciliatum Raf.; E. ciliatum subsp. glandulosum (Lehm.) Hoch & P.H. Raven and E.ciliatum subsp. watsonii (Barbey) Hoch & P.H. Raven. All three subspecies have previously been referred to other taxa and are now considered synonyms (ITIS, 2014). The native distribution of the subspecies ciliatum ranges throughout North America, East Asia and southern South America. The subspecies glandulosum occurs in northern and eastern North America and the subspecies watsonii along the west coast from California to British Columbia (USDA-NRCS, 2014).
DescriptionTop of page
E. ciliatum is a perennial herb, erect, more or loosely clumped, with basal rosettes or fleshy shoot, generally strigose in lines, glandular distally, occasionally spreading-hairy. Leaf, 1–12 cm, narrowly lanceolate to ovate, fine-toothed; veins conspicuous; petiole 0–5(8) mm. Inflorescence: densely strigose, ± spreading-hairy, generally glandular. Flower, hypanthium 0.5–2.6 mm; sepals 2–7.5 mm; petals white to rose-purple; stamens <= pistil; stigma club- or head-like. Fruit: 15–100 mm, hairy; pedicel 0–15(40) mm. Seed, 0.8–1.6 mm, ridged, hair-tuft deciduous (Jepson Flora Project, 2014).
Plant TypeTop of page Broadleaved
DistributionTop of page
E. ciliatum is native to southern parts of Canada and much of the USA, South America and East Asia. It is however listed as an endangered species in the states of Indiana and Maryland, threatened in New Hampshire and of special concern (low population numbers and restricted range) in Tennessee (USDA-NRCS, 2015).
E. ciliatum has been introduced into parts of Europe, Australia and New Zealand where it is spreading rapidly.
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.Last updated: 10 Jan 2020
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Reference||Notes|
|China||Present||CABI (Undated a)||Present based on regional distribution.|
|Japan||Present||CABI (Undated a)||Present based on regional distribution.|
|South Korea||Present||Native||USDA-ARS (2014)|
|Belgium||Present, Widespread||Introduced||Invasive||Invasive Species in Belgium (2014)|
|Croatia||Present||Introduced||Invasive||Krajšek and Jogan (2004)|
|Czechia||Present||Introduced||Invasive||Williamson et al. (2005)|
|Faroe Islands||Present||Introduced||DAISIE (2015)|
|Ireland||Present||Introduced||Invasive||Doogue et al. (1985)|
|Lithuania||Present, Widespread||Introduced||Invasive||CABI (Undated)||Original citation: Matuleviciute (2007)|
|Romania||Present||Introduced||DAISIE (2015)||Not established|
|Slovenia||Present||Introduced||Invasive||Krajšek and Jogan (2004)|
|Spain||Present||Introduced||Invasive||Fernández Alonso (2012)|
|Switzerland||Present||Introduced||Invasive||Invasive Alien Species in Switzerland (2006)||Present in the Jura and Plateau and its distribution is expanding|
|United Kingdom||Present, Widespread||Introduced||Invasive||Stace (2010)||Still spreading|
|-Channel Islands||Present||Introduced||DAISIE (2015)|
|-Northern Ireland||Present||Introduced||DAISIE (2015)|
|Canada||Present||CABI (Undated a)||Present based on regional distribution.|
|-British Columbia||Present||Native||USDA-NRCS (2014)|
|-Northwest Territories||Present||Native||USDA-NRCS (2014)|
|Saint Pierre and Miquelon||Present||Native||USDA-NRCS (2014)|
|United States||Present||CABI (Undated a)||Present based on regional distribution.|
|-California||Present, Widespread||Native||Invasive||USDA-NRCS (2014)|
|-District of Columbia||Present||Native||USDA-NRCS (2014)|
|-New Mexico||Present||Native||USDA-NRCS (2014)|
|-New York||Present||Native||USDA-NRCS (2014)|
|-North Carolina||Present||Native||USDA-NRCS (2014)|
|-North Dakota||Present||Native||USDA-NRCS (2014)|
|-Rhode Island||Present||Native||USDA-NRCS (2014)|
|-South Carolina||Present||Native||USDA-NRCS (2014)|
|-South Dakota||Present||Native||USDA-NRCS (2014)|
|-West Virginia||Present||Native||USDA-NRCS (2014)|
|-New South Wales||Present||Introduced||Council of Heads of Australasian Herbaria (2014)|
|-Queensland||Present||Introduced||Council of Heads of Australasian Herbaria (2014)|
|-South Australia||Present||Introduced||Council of Heads of Australasian Herbaria (2014)|
|-Tasmania||Present||Introduced||1919||Council of Heads of Australasian Herbaria (2014)|
|-Victoria||Present||Introduced||1969||Council of Heads of Australasian Herbaria (2014)|
|-Western Australia||Present||Introduced||1974||Council of Heads of Australasian Herbaria (2014)|
|New Zealand||Present, Widespread||Introduced||Invasive||Webb et al. (1988)|
|Argentina||Present||Native||USDA-ARS (2014)||Chubut, Cordoba, Mendoza, Neuquen, Rio Negro, San Juan, San Luis, Santa Cruz, Tierra del Fuego|
History of Introduction and SpreadTop of page
Stace (2010) reports that E. ciliatum was first recorded in Britain in 1891 and that its distribution is increasing over most of the British Isles. Preston (1988) speculated that it may have been introduction to Britain in or on timber, on the strength of two of its first three localities in Britain being timber yards. A detailed account of its spread, from its first record in Leicestershire in 1891, where it occurred initially among several other species of the same genus on the muddy shores left dry by the receding waters of a reservoir, is provided by Preston (1988). This species spread dramatically through Britain and reached Dorset and then Wales in 1942. From then on the rate of spread accelerated and by 1969 it was common throughout most of south-east England (Preston, 1988). Invasive Alien Species of Switzerland (2006) suggest that the species has been moved in soil and attached to animals, vehicles, etc., since its first arrival in Britain.
It was suggested that the presence of E. ciliatum in New Zealand may have result from introductions from Britain, but the authors mischievously speculate that the ‘possibility that it was introduced from New Zealand to Britain, rather than vice versa, cannot be ruled out’ (Raven and Raven, 1976). Given that the species occurs as a ‘wool alien’ in Britain certainly means that this could be true (Shimwell, 2006).
IntroductionsTop of page
|Introduced to||Introduced from||Year||Reason||Introduced by||Established in wild through||References||Notes|
|Natural reproduction||Continuous restocking|
|Czech Republic||1960||Yes||Williamson et al. (2005)||Accidential|
|Scotland||1957||Yes||Invasive alien species in Switzerland (2006)||Accidential|
|Tasmania||1919||Yes||Council of Heads of Australasian Herbaria (2014)|
Risk of IntroductionTop of page
There is little doubt that A. ciliatum will continue to spread across land borders into other European countries to which the large number of seeds could be carried by the wind, on the tyres of vehicles or in their slipstream. Its spread will also continue within those countries where its distribution is at present limited or patchy.
HabitatTop of page
In its native range of California, USA, E. ciliatum is found throughout the state up to 4100 m in altitude, in moist or dry disturbed areas. This includes meadows and wetlands, agricultural areas, wet and moist sites, streambanks, ditches, irrigation canals as well as in orchards, nurseries, vineyards and landscaped areas (UCIPM, 2014). It has been suggested that in North America it occupies a range of soil types, occurring on light or heavy, calcareous or non-calcareous soils (Wiegand and Eames, 1926). On Vancouver Island and southern British Columbia it occurs in disturbed areas, roadsides, fields and ditches (Klinkenberg, 2014). Similarly in China it grows in moist, disturbed places along streams, rivers, roadside ditches, slopes and seeps (Flora of China Editorial Committee, 2014).
In Britain, to which it was introduced many years ago, E. ciliatum has spread into woodlands and many man-made or modified habitats such as railway banks, roadsides, river-banks, gardens and plant nurseries (Myerscough and Whitehead, 1966; Stace, 2010). In Lithuania, Matuleviciute (2007), found that plants were most frequently found in areas occupied by wet natural and semi-natural open wet habitats, often on the banks of waterways or in periodically flooded habitats. In Lithuania, as elsewhere, E. ciliatum prefers well-lit, moist, mesotrophic or eutrophic habitats with low acid to neutral soil reaction (Matuleviciute and Sprainaityte, 2010). However, in Slovenia and Croatia it is found in dry meadows and shrubland (Krajsek and Jogan, 2004). Havaux (1990) commented that E. ciliatum was very common in Northern France and Belgium, where it grows rapidly on poor and marginal lands and added that its high competitiveness was presumably due to its tolerance of unfavourable growth conditions, especially the very low light conditions needed for growth (Havaux, 1990).
In New Zealand, according to Webb et al. (1988) it is similarly found on waste land, especially where moist, in and around swamps, river beds and ponds and in cultivated soil.
Habitat ListTop of page
|Terrestrial – Managed||Cultivated / agricultural land||Present, no further details||Natural|
|Protected agriculture (e.g. glasshouse production)||Present, no further details||Natural|
|Managed forests, plantations and orchards||Present, no further details||Natural|
|Rail / roadsides||Present, no further details||Natural|
|Urban / peri-urban areas||Present, no further details||Natural|
|Terrestrial ‑ Natural / Semi-natural||Riverbanks||Present, no further details||Natural|
Biology and EcologyTop of page
The Jepson Flora Project (2014) has reported a diploid number of 2n=36 for E. ciliatum.
A number of hybrids of E. ciliatum with other Epilobium species have been reported. Seavey (1993) found that E. ciliatum can successfully hybridize with E. luteum producing fertile hybrids. He also found field-collected plants of E. treleasianum from the Olympic Mountains in Washington State that were clearly the result of natural hybridization between E. ciliatum subsp. glandulosum and E. luteum (Seavey, 1993). Kitchener and McKean (1998) also reported that in New Zealand E. ciliatum had hybridized with the native E. brunnescens. Such hybrids were first reported in Britain in 1995 (Kitchener and McKean, 1998) and were formally recognised as E. x brunnatum. Since E. ciliatum is still spreading rapidly in Britain, Kitchener and McKean (1988) speculate that hybrids are likely to become more common in future.
In California E. ciliatum flowers between June and September (UCIPM, 2014) and a single plant can produce up to 60,000 seeds in a season (Altland and Cramer, 2006; Altland, 2007). The seeds are small and light, weighing just 0.062 mg, with a rate of fall in still air of 16 cm sec-1 (Myerscough and Whitehead, 1966). Seeds of E. ciliatum can germinate under a relatively wide range of temperatures and light. This means that germination can occur throughout the spring and summer growing seasons in northern climates and virtually year-round in protected container crops. Altland and Cramer (2006) observed that the seeds are capable of germination in much drier soil that other species in the same genus, a conclusion also reached by Myerscough and Whitehead (1966). Seeds can germinate in full sun or partial shade at 84% of full sun and they can germinate at temperatures from 4-36°C although germination is reduced as temperatures approaching 30°C (Altland and Cramer, 2006; Altland, 2007). Germination of ripe seed from recently opened seed pods occurred within four days of sowing in full sun and in less than seven days in partial shade (Altland and Cramer, 2006; Altland, 2014). Seeds exposed to a pH of 3.0 did not germinate, even after subsequent transfer to pH 5.0 and those in a pH 4.0 solution had their germination reduced to less than 50%. Those seeds in solutions at pH 5.0, 4.5 or 4.0 germinated quickly and almost completely (Myerscough and Whitehead, 1966).
Plants can flower in five to six weeks from germination and then produce mature seed four weeks later. E. ciliatum therefore needs only about nine to ten weeks for plants to germinate, mature and produce another generation of seeds, allowing several generations in a single growing season.
E. ciliatum is self-pollinating and is visited by relatively few insects (small halictid bees and a species of Bombus) (Parket et al., 1995). A study looking at the reproductive allocation and fitness consequences of selfing can be found in Parket et al. (1995).
Physiology and Phenology
In England, Myerscough and Whitehead (1966) reported that the initial growth form of the seedlings depends on day length. Seedlings established in the autumn form rosettes, but those established in early summer form an elongated shoot system from the start of growth. In the latter case flower buds are formed after the production of the first four or five pairs of opposite leaves, about four to five weeks after germination. At this stage side shoots are produced and these also elongate and flower. Flowering occurs about 38 days after germination. Ripe capsules burst and shed seed about four weeks after the flowers open. Winter rosettes produced from the compact buds in the axils of cotyledons and lower leaves remain unchanged in late spring, but the terminal buds of the main axis and side shoots elongate into long internodes and flower and fruit in the same way as early summer established seedlings (Myerscough and Whitehead, 1966).
E. ciliatum shows strong apical dominance, with the main shoot suppressing the growth of lateral branches, so long as the growing point remains intact (Irwin and Aassen, 1996). Clipping the apex results in a reduction in plant height, but stimulates branched stem numbers and thus increases total branch length (Irwin and Aassen, 1996). However it was concluded that increases in nutrient level decreased the strength of apical dominance. The benefits of apical dominance were most evident for competing plants grown under high nutrient conditions where competition for light is expected to be most intense (Irwin and Aassen, 1996). Havaux (1990) suggested that the ability of E. ciliatum to grow under extreme shade conditions may be explained, at least partly, by its preservation of high oxygen yield at low photon flux densities.
According to Altland and Cramer (2006) the species can also form turions on its roots, which may also be another means of reproduction. However, in contrast to this it has been suggested that E. ciliatum subsp. ciliatum does not ‘produce underground winter buds (turions)’, but rather that E. ciliatum subsp. glandulosum is characterised by its underground turions (Minnesota Seasons, 2014)
There is some conflict with regards to the longevity of the seeds. Florabase (2014) says that the seedbanks of E. ciliatum are short-lived, possibly days to one year. Myerscough and Whitehead (1966) however, state that the seeds last for several years in both laboratory and natural conditions. The plants themselves are perennials, but probably short-lived ones, forming rosettes as over-wintering structures.
Population Size and Structure
Estimated doubling times of E. ciliatum in terms of area occupied were 2.25 years in the Czech Republic and 4.67 years in Britain and Ireland (Williamson et al., 2005). However, the authors said their overall results ‘produced rather few clear explanations’ but suggested that economic and landscape factors are important in determining the rate of spread (Williamson et al., 2005).
In Lithuania, E. ciliatum most frequently occurs in plant communities belonging to the Molinio-Arrhenanthereta, Phragmito-Magnocaticetea and Isoeto-Nanojuncetea classes and communities of wetter habitats (Matuleviciute, 2007). Its most common associates are Phragmites australis, Carex gracilis [C. mucronata], C. paniculata, Phalaris arundinacea and Glyceria maxima.
A study by Myerscough and Whitehead (1967) looked at the impact of reducing nutrient availability on E. ciliatum and found that the size and degree of development of the plants was affected. E. ciliatum is well adapted to growth under shady conditions and produces larger leaves to compensate (Myerscough and Whitehead, 1967). However growth with just 10% light levels significantly decreased the dry weigh of plants when compared with 100%, 70% and 43% light levels (Myerscough and Whitehead, 1967).
ClimateTop of page
|Cf - Warm temperate climate, wet all year||Preferred||Warm average temp. > 10°C, Cold average temp. > 0°C, wet all year|
|Cs - Warm temperate climate with dry summer||Preferred||Warm average temp. > 10°C, Cold average temp. > 0°C, dry summers|
|Cw - Warm temperate climate with dry winter||Preferred||Warm temperate climate with dry winter (Warm average temp. > 10°C, Cold average temp. > 0°C, dry winters)|
Means of Movement and DispersalTop of page
The seeds of E. ciliatum are very light and attached to a tuft of hair which aids in wind dispersal. In Oregon this occurs from June to September (Altland and Cramer, 2006). Compact buds also develop in the axils of the cotyledons and lower leaves. These are readily detached and could provide a mechanism for local spread.
The seeds may become attached to the wheels of vehicles or even blown along in their slipstreams (Preston, 1988).
The seeds are very small and light and could easily be accidentally carried in baggage or on clothing.
Intentional introduction of E. ciliatum is unlikely as the plants are neither showy nor have a widespread reputation as medicinal plants outside their native range.
Pathway VectorsTop of page
Impact SummaryTop of page
Economic ImpactTop of page
In Oregon, USA, its native range, E. ciliatum has been described as ‘one of the most difficult weeds to control in container crops and is among the top five weed species in Oregon nurseries’ (Altland and Cramer, 2006).
In Western Australia, where it was introduced, it is a common weed of nurseries and orchards (FloraBase, 2014). In Belgium it occurs as a weed in tree nurseries, fruit plantations, maize and sites of total vegetation control (Bulcke et al., 1987). As a result there is some economic impact associated with controlling this species in both its introduced and native range however no data detailing this is available.
Environmental ImpactTop of page
In countries to which it has been introduced, it is mostly a problem in man-made habitats but can also invade woodlands, damp marshland and the margins of rivers and ponds. Here it may play a crucial part in displacing native vegetation. Its rapid growth allows it to outcompete many smaller container shrubs and herbaceous perennials. A study by Willoughby et al. (2006) found that E. ciliatum is likely to affect the early growth of young tree plants such as Betula pendula by decreasing both height and diameter increment of plants.
Although rare, it is possible for E. ciliatum to form hybrids with several different Epilobium species (Invasive Species in Belgium, 2015). This may cause rare Epilobium species to suffer as a result of outbreeding (Invasive Species in Belgium, 2015).
Risk and Impact FactorsTop of page Invasiveness
- Invasive in its native range
- Proved invasive outside its native range
- Has a broad native range
- Abundant in its native range
- Highly adaptable to different environments
- Pioneering in disturbed areas
- Tolerant of shade
- Highly mobile locally
- Benefits from human association (i.e. it is a human commensal)
- Fast growing
- Has high reproductive potential
- Has propagules that can remain viable for more than one year
- Has high genetic variability
- Competition - shading
- Interaction with other invasive species
- Rapid growth
- Highly likely to be transported internationally accidentally
- Difficult to identify/detect as a commodity contaminant
- Difficult to identify/detect in the field
- Difficult/costly to control
UsesTop of page
According to Moerman (2014), E. ciliatum subsp. ciliatum is used by some native North Americans to treat leg pain where it is applied as a lotion and poultice of roots to muscular cramps. An infusion of roots of E. ciliatum is also used to treat diarrhoea.
Uses ListTop of page
- Source of medicine/pharmaceutical
Similarities to Other Species/ConditionsTop of page
E. ciliatum is similar in appearance to a number of different species within the genus Epilobium. In Minnesota, E. ciliatum is often confused with E. coloratum, E. leptophyllum and E. strictum (Minnesota Seasons, 2014). These can be distinguished from each other by morphological characteristics. E. coloratum has stems and leaves often tinted purple, leaf margins more densely toothed and with shorter fruit. E. leptophyllum has narrower leaves, leaf margins not toothed but rolled back towards the underside and the upper leaf surface is covered in straight, stiff, sharp appressed hairs. E. strictum has an unbranched stem or has just a few branches. The upper and middle stem leaves are obviously alternate, leaves are narrower and are not toothed and are rolled backwards towards the underside and the upper leaf surface is densely covered in straight, spreading or ascending hairs.
E. ciliatum may also be confused with E. brachycarpum. Key differences can be found in UCIPM (2014).
In Switzerland, E. ciliatum is mostly likely to be confused with E. obscurum but the former has larger stems, is glandular on top and has white flowers (Invasive Alien Species in Switzerland, 2006).
Prevention and ControlTop of page
Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.
Cultural Control and Sanitary Measures
A study in Poland by Przepiorkowski and Gorski (1994) examined the effects of residues of rye (Secale cereale) on both triazine-resistant and triazine-susceptible Epilobium species (species not specified). They found that soil containing rye root residues inhibited germination of Epilobium seeds by up to 50% with the highest rate of rye applied. Aqueous extracts of rye shoot tissue were also found to inhibit germination, even at low concentrations (Przepiorkowski and Gorski, 1994). Planting seedlings of Epilobium species into soils containing rye roots left after the tops had been severed also resulted in lower dry weights after six weeks of growth. Thus interspersing rye into crop rotations, as is often done (Przepiorkowski and Gorski, 1994), could perhaps be used to limit the growth of populations of species of Epilobium.
Recommendations in Western Australia suggest that plants should be prevented from seeding and that small or isolated infestations of seedlings should be removed by hand. If larger plants are removed it is important not to leave any fragments of the crown behind as they may regrow (FloraBase, 2014).
Le Fer and Parker (2005), evaluated the effects of prescribed burns at different times of the year on chaparral species, of which E. ciliatum is one. They heated seeds of 13 species moist and dry to determine the moisture effect on heated seeds. Of the species tested E. ciliatum was the most tolerant of heat when dry with germination only dropping significantly at 110oC. However under moist conditions germination of the seeds of this species were significantly reduced at 70oC. As a result it was suggested that spring burns, when soil moisture is high, is probably more damaging to the natural vegetation than dry season burns (Le Fer and Parker, 2005). This helps to maintain historical fire regimes and thus decrease alterations to the ecosystem’s dynamics.
Chemical control of E. ciliatum is tricky as it is resistant to a number of herbicides. For example, Heap (2015) reported resistance to atrazine and simazine in Belgium in 1980, to paraquat in Belgium in 1982, to atrazine in Poland in 1995 and to simazine and paraquat in the UK in 1981 and 1989 respectively. It has been suggested that seedlings could be sprayed with glyphosate. However older, mature plant can tolerate glyphosate and established plants will often re-sprout after treatment (FloraBase, 2014). However, Altland and Cramer (2006) tested the effects of a range of granular and liquid herbicide formulations on the pre-emergent control of E. ciliatum. Of the granular formulations, oxadiazon, oxyfluorfen plus pendimethalin and oxydiazon plus prodiamine all reduced numbers of E. ciliatum three weeks after treatment. After eight weeks, the greatest reductions in shoot dry matter were given by oxadiazon, oxydiazon plus prodiamine, oxyfluorfen plus oryzalin and flumioxazin. This treatment was found to be effective for control E. ciliatum in container plants in nurseries, however it is not known whether this method would be suitable in more natural environments.
It has been suggested that herbicides alone will not provide effective control of E. ciliatum and that a combination of good hygiene and herbicide management is required (FloraBase, 2014). Altland and Cramer (2006) suggested that control should involve using a combination of hand pulling or post-emergent applications of glyphosate.
ReferencesTop of page
Altland J, 2007. Northern willowherb control in nursery containers. Oregon, USA: Oregon State University. www.cwss.org/uploaded/media_pdf/6473-54_2007.pdf
Altland J, 2014. Northern-willowherb management. Oregon, USA: Oregon State University. http://oregonstate.edu/dept/nursery-weeds/feature_articles/willowherb/willowherb_control_page.html
Atland J; Cramer E, 2006. Control of northern willowherb in nursery containers. Journal of Environmental Horticulture, 24(3):143-148.
Bulcke R; Verstraete F; Himme Mvan; Stryckers J, 1987. Biology and control of Epilobium ciliatum Rafin. (syn.: E. adenocaulon Hausskn.). In: Proceedings of a meeting of the EC Experts' Group, Dublin, 12-14 June 1985. Rotterdam, A.A. Blakema, Netherlands 57-67.
Council of Heads of Australasian Herbaria, 2014. Australia's virtual herbarium, Australia. http://avh.ala.org.au
DAISIE, 2015. Delivering Alien Invasive Species Inventories for Europe. European Invasive Alien Species Gateway. www.europe-aliens.org/default.do
Doogue D; Kelly DL; Wyse Jackson PS, 1985. The progress of Epilobium ciliatum Rafin. (E. adenocaulon Hausskn.) in Ireland, with some notes on its hybrids. The Irish Naturalists' Journal, 21(10):444-446.
Fernández Alonso JL, 2012. Epilobium ciliatum Rafin. (Onagraceae), a new adventive species potentially invasive in the Iberian Peninsula. (Epilobium ciliatum Rafin. (Onagraceae), una nueva adventicia potencialmente invasora en la Peninsula Ibérica.) Acta Botanica Malacitana, 37:179-184. http://www.uma.es/estudios/Departamentos/BiolVeg/03Rev/00HRev/01Rev.html
Flora of China Editorial Committee, 2014. Flora of China. St. Louis, Missouri and Cambridge, Massachusetts, USA: Missouri Botanical Garden and Harvard University Herbaria. http://www.efloras.org/flora_page.aspx?flora_id=2
Florabase, 2014. Flora of Western Australia. Perth, Western Australia: Department of Environment and Conservation. http://florabase.au/ http://florabase.dpaw
Heap I, 2015. The international survey of herbicide resistant weeds. www.weedscience.org
Invasive Alien Species in Switzerland, 2006. Inventory of alien species and their threat to biodiversity and economy in Switzerland. Bern, Switzerland: Federal Office for the Environment FOEN. http://www.bafu.admin.ch/publikationen/publikation/00028/index.html?lang=en&download=NHzLpZig7t,lnp6I0NTU042l2Z6ln1ad1IZn4Z2qZpnO2Yuq2Z6gpJCGdnt4hGym162dpYbUzd,Gpd6emK2Oz9aGodetmqaN19XI2IdvoaCVZ,s-.pdf
Invasive Species in Belgium, 2014. Invasive species in Belgium. Belgium: Belgian Biodiversity Platform. http://ias.biodiversity.be/
ITIS, 2014. Integrated Taxonomic Information System. http://www.itis.gov
Jauzein P, 1988. [English title not available]. (Quelque adventices méconnues de la flore française.) Annales ANPP (Association Nationale Pommes Poires), 3. 199-208.
Jepson Flora Poject, 2014. Jepson eFlora. Berkeley California, USA: Univeristy of California. http://ucjeps.berkeley.edu/jepson_flora_project.html
Klinkenberg B, 2014. Electronic Atlas of the Plants of British Columbia. E-Flora BC. Vancouver, British Columbia, Canada: Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia. www.eflora.bc.ca/
Matuleviciute D; Sprainaityte S, 2010. Population dynamics of Epilobium ciliatum in fire places in Kamanos raised bog: 5-year study (2004-2008). Acta Biologica Universitutis Dauguvpiliereslis, 2:29-35.
Minnesota Seasons, 2014. American willowherb: (Epilobium ciliatum ssp. ciliatum). Minnesota, USA. http://minnesotaseasons.com/Plants/American_willowherb.html
Moerman D, 2014. Native American ethnobotany. http://herb.umd.umich.edu/. Dearborn, Michigan, USA: University of Michigan-Dearborn.
Myerscough PJ; Whitehead FH, 1966. Comparative biology of Tussilago farfara L., Chamaenerion angustifolium (L) Scop., Epilobium montanum L. and Epilobium adenocaulon Hausskn. 1. General biology and germination. New Phytologist, 65(2):192-210.
Myerscough PJ; Whitehead FH, 1967. Comparative biology of Tussilago farfara L., Cham-aenerîon angustifolium (L.) Scop., Epilobium mon-tanum L., and Epilobium adenocaulon Hausskn. 2. Growth and ecology. New Phytologist, 66(4):785-823.
Parker IM; Nakamura RR; Schemske DW, 1995. Reproductive allocation and the fitness consequences of selfing in two sympatric species of Epilobium (Onagraceae) with contrasting mating systems. American Journal of Botany, 82(8):1007-1016.
Preston CD, 1988. The spread of Epilobium ciliatum Raf in the British Isles. Watsonia, 17(3):279-288.
Raven PH; Raven TE, 1976. The genus Epilobium in Australasia. New Zealand DSIR Bulletin 216.
Stace C, 2010. New flora of the British Isles. Cambridge, UK: Cambridge University Press, 1232 pp.
The Plant List, 2013. The Plant List: a working list of all plant species. Version 1.1. London, UK: Royal Botanic Gardens, Kew. http://www.theplantlist.org
UCIPM, 2014. Willowherbs (Epilobium ciliatum, E. brachycarpum). California, USA: University of California Agriculture and Natural Resources. http://www.ipm.ucdavis.edu/PMG/WEEDS/willowherbs.html
USDA-ARS, 2014. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.aspx
USDA-NRCS, 2014. The PLANTS Database. Baton Rouge, USA: National Plant Data Center. http://plants.usda.gov/
Wiegand KM; Eames AJ, 1926. The flora of the Cayuga Lake Basin, New York: vascular plants. New York, USA: Cornell University. http://bhort.bh.cornell.edu/intro.htm
Williamson M; Pysek P; Jarosík V; Prach K, 2005. On the rates and patterns of spread of alien plants in the Czech Republic, Britain, and Ireland. Écoscience, 12(3):424-433. http://www.ecoscience.ulaval.ca
Willoughby I; Clay DV; Dixon FL; Morgan GW, 2006. The effect of competition from different weed species on the growth of Betula pendula seedlings. Canadian Journal of Forest Research, 36(8):1900-1912. http://cjfr.nrc.ca
CABI, Undated. Compendium record. Wallingford, UK: CABI
CABI, Undated a. CABI Compendium: Status inferred from regional distribution. Wallingford, UK: CABI
Council of Heads of Australasian Herbaria, 2014. Australia's virtual herbarium., Australia: http://avh.ala.org.au
DAISIE, 2015. Delivering Alien Invasive Species Inventories for Europe. http://www.europe-aliens.org/
Doogue D, Kelly DL, Wyse Jackson PS, 1985. The progress of Epilobium ciliatum Rafin. (E. adenocaulon Hausskn.) in Ireland, with some notes on its hybrids. In: The Irish Naturalists' Journal, 21 (10) 444-446.
Fernández Alonso J L, 2012. Epilobium ciliatum Rafin. (Onagraceae), a new adventive species potentially invasive in the Iberian Peninsula. (Epilobium ciliatum Rafin. (Onagraceae), una nueva adventicia potencialmente invasora en la Peninsula Ibérica.). Acta Botanica Malacitana. 179-184. http://www.uma.es/estudios/Departamentos/BiolVeg/03Rev/00HRev/01Rev.html
Invasive Alien Species in Switzerland, 2006. Inventory of alien species and their threat to biodiversity and economy in Switzerland., Bern, Switzerland: Federal Office for the Environment FOEN. http://www.bafu.admin.ch/publikationen/publikation/00028/index.html?lang=en&download=NHzLpZig7t,lnp6I0NTU042l2Z6ln1ad1IZn4Z2qZpnO2Yuq2Z6gpJCGdnt4hGym162dpYbUzd,Gpd6emK2Oz9aGodetmqaN19XI2IdvoaCVZ,s-.pdf
Invasive Species in Belgium, 2014. Invasive species in Belgium., Belgium: Belgian Biodiversity Platform. http://ias.biodiversity.be/
Stace C, 2010. New flora of the British Isles., UK: Cambridge University Press.
USDA-ARS, 2014. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysimple.aspx
USDA-NRCS, 2014. The PLANTS Database. Greensboro, North Carolina, USA: National Plant Data Team. https://plants.sc.egov.usda.gov
Webb C J, Sykes W R, Garnock-Jones P J, 1988. Flora of New Zealand, Volume IV: Naturalised pteridophytes, gymnosperms, dicotyledons. Christchurch, New Zealand: Botany Division, DSIR. 1365 pp. http://floraseries.landcareresearch.co.nz/pages/Book.aspx?fileName=Flora%204.xml
Williamson M, Pyšek P, Jarošík V, Prach K, 2005. On the rates and patterns of spread of alien plants in the Czech Republic, Britain, and Ireland. Écoscience. 12 (3), 424-433. http://www.ecoscience.ulaval.ca
ContributorsTop of page
04/08/2014 Original text by:
Ian Popay, Landcare Research, New Zealand
Distribution MapsTop of page
Unsupported Web Browser:
One or more of the features that are needed to show you the maps functionality are not available in the web browser that you are using.
Please consider upgrading your browser to the latest version or installing a new browser.
More information about modern web browsers can be found at http://browsehappy.com/