Trifolium angustifolium (narrow-leaf clover)
- Summary of Invasiveness
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Plant Type
- Distribution Table
- History of Introduction and Spread
- Habitat List
- Growth Stages
- Biology and Ecology
- Latitude/Altitude Ranges
- Air Temperature
- Soil Tolerances
- Means of Movement and Dispersal
- Pathway Causes
- Pathway Vectors
- Plant Trade
- Impact Summary
- Impact: Economic
- Impact: Environmental
- Threatened Species
- Risk and Impact Factors
- Uses List
- Similarities to Other Species/Conditions
- Prevention and Control
- Principal Source
- 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
- Trifolium angustifolium L.
Preferred Common Name
- narrow-leaf clover
International Common Names
- English: narrow clover; narrowleaf crimson clover; narrow-leaf crimson clover; narrow-leaved clover; narrow-leaved crimson clover
Local Common Names
- Sweden: luddklöver
Summary of InvasivenessTop of page
The narrow-leaf clover Trifolium angustifolium is an annual legume native to central, southern and eastern Europe, western Asia and North Africa. It has been introduced elsewhere and is valued for forage and pasture improvement. It has become an environmental weed in a few countries such as Australia, Japan and Chile but has not been reported as an aggressive invader. It is included in the IUCN Red List (Least Concern) for its value as a genetic resource for forage legumes.
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Spermatophyta
- Subphylum: Angiospermae
- Class: Dicotyledonae
- Order: Fabales
- Family: Fabaceae
- Subfamily: Papilionoideae
- Genus: Trifolium
- Species: Trifolium angustifolium
Notes on Taxonomy and NomenclatureTop of page
Trifolium angustifolium is one of about 300 species in this genus of the Fabaceae and is a wild relative of the cultivated crops crimson clover (T. incarnatum) and red clover (T. pratense) (Osborne, 2013). The following subspecies are included in The Plant List (2013): T. angustifolium subsp. intermedium (Guss.) Ponert and subsp. pamphylicum (Boiss. & Heldr.) Ponert. It is commonly referred to as narrow-leaf clover or narrow-leaved crimson clover (EPPO, 2014). The common name ‘white clover’ is listed in the IUCN Red List (Lopez Poveda, 2012; Osborne, 2013), but T. angustifolium has pink flowers and the name ‘white clover’ is usually reserved for T. repens.
DescriptionTop of page
T. angustifolium is an annual herb growing to about 0.1- 0.6 m high. Its inflorescence is a cylindrical spike of pale-pink flowers, 1-5 cm in height, each flower having a calyx of sepals that have long, needle-like lobes which harden into bristles when the plant dries. Its herbage is of a hairy texture with solid stems and alternate trifoliate leaves with linear to lance-shaped leaflets up to 4.5 cm long (Webb et al., 1988).
Plant TypeTop of page
DistributionTop of page
T. angustifolium is native to central, eastern and southern Europe and the Mediterranean regions of Africa and Asia (Harshberger, 1922; Blake, 1923; Zohary and Heller, 1984; Osborne, 2013). There is some uncertainty about its native/introduced status in Belarus, Ukraine, Switzerland, Madeira and the Canary Islands (Lopez Poveda, 2012; Osborne, 2013; USDA-ARS, 2016). It has naturalized in some countries and is noted as an environmental weed in Australia and Japan (Auld et al., 2003) and Chile (Marticorena and Quezada, 1985). This species has not been reported as an aggressive invader.
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: 14 Dec 2020
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Reference||Notes|
|Japan||Present||Introduced||Recorded as a weed|
|Serbia and Montenegro||Present||Native|
|United States||Present||Present based on regional distribution.|
|Australia||Present||Introduced||Recorded as a weed|
|-New South Wales||Present||Introduced|
|Chile||Present||Introduced||Recorded as a weed in central Chile|
History of Introduction and SpreadTop of page
T. angustifolium was recorded for the first time in California, USA, in 1922 (Blake (1923).
HabitatTop of page
Habitat ListTop of page
|Terrestrial||Managed||Managed grasslands (grazing systems)||Present, no further details||Harmful (pest or invasive)|
|Terrestrial||Managed||Managed grasslands (grazing systems)||Present, no further details||Productive/non-natural|
|Terrestrial||Managed||Disturbed areas||Present, no further details||Harmful (pest or invasive)|
|Terrestrial||Managed||Disturbed areas||Present, no further details||Productive/non-natural|
|Terrestrial||Managed||Rail / roadsides||Present, no further details||Harmful (pest or invasive)|
|Terrestrial||Managed||Rail / roadsides||Present, no further details||Productive/non-natural|
|Terrestrial||Natural / Semi-natural||Natural forests||Present, no further details||Natural|
|Terrestrial||Natural / Semi-natural||Natural grasslands||Present, no further details||Natural|
|Terrestrial||Natural / Semi-natural||Rocky areas / lava flows||Present, no further details||Harmful (pest or invasive)|
|Terrestrial||Natural / Semi-natural||Rocky areas / lava flows||Present, no further details||Productive/non-natural|
|Littoral||Coastal areas||Present, no further details||Harmful (pest or invasive)|
|Littoral||Coastal areas||Present, no further details||Productive/non-natural|
Growth StagesTop of page
Biology and EcologyTop of page
T. angustifolium reproduces sexually through seed. The seed size is relatively small compared with other annual clovers and is associated with high fecundity (Norman et al., 2005).
Physiology and Phenology
The germination rate of T. angustifolium seed is low in unsuitable environments with growth being directly related to availability of water (Western Australian Herbarium, 2015). This species has long-term hardseededness which allows risk of failure to spread across seasons (Norman et al., 2005) as the hard coat makes this plant very tolerant of abiotic factors. Seeds of T. angustifolium have been found to persist in the soil of forests despite being absent above ground (Erfanzadeh et al., 2013). Studies on germination have shown that smoke and charred wood solutions enhance seed germination but this is negatively affected by exogenous applications of nitrogenous compounds and/or salts (Pérez-Fernández and Rodríquez-Echeverría, 2003).
T. angustifolium has a symbiotic association with nitrogen-fixing Rhizobium bacteria in the soil which makes it possible for this plant to colonize disturbed areas and nutrient-poor soils (Driouech et al., 2008).
T. angustifolium prefers dry, usually nutrient-poor, disturbed, acid soils (Fletcher, 2007). There is little information on tolerance of frost and drought, however, the closely related crimson clover T. incarnatum is considered sensitive to these abiotic factors (Frame, 2015).
ClimateTop of page
|BS - Steppe climate||Preferred||> 430mm and < 860mm annual precipitation|
|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)|
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|
|Absolute minimum temperature (ºC)||-3|
|Mean annual temperature (ºC)||15||16|
|Mean maximum temperature of hottest month (ºC)||22||35|
|Mean minimum temperature of coldest month (ºC)||0||18|
RainfallTop of page
|Parameter||Lower limit||Upper limit||Description|
|Mean annual rainfall||400||900||mm; lower/upper limits|
Soil TolerancesTop of page
Special soil tolerances
Means of Movement and DispersalTop of page
Pathway CausesTop of page
Pathway VectorsTop of page
Plant TradeTop of page
|Plant parts liable to carry the pest in trade/transport||Pest stages||Borne internally||Borne externally||Visibility of pest or symptoms|
|True seeds (inc. grain)||seeds||Yes|
Impact SummaryTop of page
|Environment (generally)||Positive and negative|
Impact: EconomicTop of page
The positive economic impact of T. angustifolium relates to its forage value and use as a nitrogen-fixing green manure. No information has been found on economic impact when it is present as a weed.
Impact: EnvironmentalTop of page
Impact on Habitats
T. angustifolium is adapted to nutrient-poor soils (a characteristic of Mediterranean environments) (Muensher, 1955; Webb et al., 2003). This attribute enables it to establish in areas which have low levels of vegetation providing the potential for moderate changes in the density or cover of the herbaceous layer.
Through the symbiotic association with nitrogen-fixing Rhizobium bacteria, there is also potential for T. angustifolium to alter the soil nutrient balance where introduced. It is able to fix between 131.7 and 146.7kg/ha/year (Driouech et al., 2008).
Impact on Biodiversity
T. angustifolium has a relatively large inflorescence, long flowering period and high nectar production which attracts bees. This may indirectly affect the pollination of domesticated crops and native plants.
The increased soil nitrogen resulting from an introduced legume may alter the plant community and aid the establishment of other alien plants that are more invasive.
In California, USA, the threatened annual Halocarpha macradenia (Santa Cruz tarplant) is disadvantaged by overgrowth by non-native species including T. angustifolium (Holl and Hayes, 2005; US Fish and Wildlife Service, 2014).
Threatened SpeciesTop of page
Risk and Impact FactorsTop of page
- Fast growing
- Has high reproductive potential
- Has propagules that can remain viable for more than one year
- Increases vulnerability to invasions
- Modification of nutrient regime
- Threat to/ loss of endangered species
- Threat to/ loss of native species
- Competition (unspecified)
- Highly likely to be transported internationally deliberately
UsesTop of page
T. angustifolium has long been utilized as self-seeding forage in making hay or direct grazing. Studies conducted by Kamalak and Canbolat (2010) on its nutritive value showed that it contains high levels of crude proteins. However with advancing maturity, its nutritive value decreases. Its low tannin levels enable it to be used as an alternative legume to reduce bloating risk in ruminants grazed on pastures.
Its rapid establishments and association with nitrogen-fixing bacteria make T. angustifolium suitable as a winter cover crop to produce green manure in organic or low-input vegetable production systems in Mediterranean regions (Driouech et al., 2008). It is also valued for honey production.
T. angustifolium is also recognized as a potential gene donor to other cultivated clovers (T. incarnatum and T. pratense) and it has been included in the IUCN Red List for this reason (Osborne, 2013).
This plant is traditionally used to treat diarrhoea and relieve stomach aches (Rauter et al., 2002).
Uses ListTop of page
Animal feed, fodder, forage
- Gene source
Human food and beverage
- Honey/honey flora
Similarities to Other Species/ConditionsTop of page
T. angustifolium can be distinguished from other Trifolium species by its long pink flower heads and narrow leaflets. An identification key to the clovers of New Zealand was presented by Healy (1961).
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
Normal cultivation practices effectively control clovers, including T. angustifolium, in crops. When carried out before flowering, the seed bank is reduced (UC IPM, 2014). Mulching of invaded areas using compost, wood chips or organic mulch helps reduce weed spread by limiting the amount of light available. Mulch also preserves moisture for the cultivated crops giving them a competitive edge over T. angustifolium. Changing the fertilizer programme, by increasing the rates of nitrogen and reducing phosphorous, helps control re-infestation by T. angustifolium and other leguminous weeds (UC IPM, 2014).
T. angustifolium has a hard seed coat which means that composting and soil solarization do not reduce seed viability (UC IPM, 2014).
Where T. angustifolium has spread to new areas, especially cultivated plots, hand pulling before flowering or seed set may reduce spread (UC IPM, 2014).
As grazing sheep are known to disperse seeds which adhere to their fleece, avoid livestock in areas colonized by T. angustifolium after flowering (DiTomaso and Healy, 2007).
Grazing animals will feed on T. angustifolium, however, as mentioned above, there is a risk that they aid seed dispersal (Manzano and Malo, 2006). No biological control using arthropods or pathogens has been considered as this plant is often used for pasture or soil improvement.
Pre-emergent and/or post-emergent herbicides such as glyphosate have been used against clovers. However, these weeds tend to regrow after chemical treatment (UC IPM, 2014). Western Australian Herbarium (2015) recommends glyphosate before flowering and spot spray with clopyralid up to the 6-leaf stage for control of T. angustifolium.
ReferencesTop of page
AVH, 2015. Australia's Virtual Herbarium. Canberra, ACT, Australia: Council of Heads of Australasian Herbaria. http://avh.chah.org.au/
Blake SF, 1923. Two Mediterranean clovers new to the United States. Science, 57(1484):665-665.
CCDB, 2015. Chromosome Counts Database. http://ccdb.tau.ac.il/home/
DiTomaso JM; Healy AH, 2007. Weeds of California and other Western States, Volume 1. USA: University of California Press.
Driouech N; Fayad FA; Ghanem A; Al-Bitar L, 2008. Agronomic performance of annual self-reseeding legumes and their self-establishment potential in the Apulia region of Italy. In: Cultivating the future based on science. Volume 1: Organic Crop Production. Proceedings of the Second Scientific Conference of the International Society of Organic Agriculture Research (ISOFAR), held at the 16th IFOAM Organic World Conference in Cooperation with the International Federation of Organic Agriculture Movements (IFOAM) and the Consorzio ModenaBio in Modena, Italy, 18-20 June, 2008 [ed. by Neuhoff, D.\Halberg, N.\Alföldi, T.\Lockeretz, W.\Thommen, A.\Rasmussen, I. A.\Hermansen, J.\Vaarst, M.\Lueck, L.\Caporali, F.\Jensen, H. H.\Migliorini, P.\Willer, H.]. Bonn, Germany: International Society of Organic Agricultural Research (ISOFAR), 396-399.
EPPO, 2014. PQR database. Paris, France: European and Mediterranean Plant Protection Organization. http://www.eppo.int/DATABASES/pqr/pqr.htm
Erfanzadeh R; Kahnuj SHH; Azarnivand H; Pétillon J, 2013. Comparison of soil seed banks of habitats distributed along an altitudinal gradient in northern Iran. Flora (Jena), 208(5/6):312-320. http://www.sciencedirect.com/science/journal/03672530
Fernández-Lugo S; Nascimento Lde; Mellado M; Arévalo JR, 2011. Grazing effects on species richness depends on scale: a 5-year study in Tenerife pastures (Canary Islands). Plant Ecology, 212(3):423-432. http://springerlink.metapress.com/link.asp?id=100328
Fletcher N, 2007. Mediterranean wildflowers. China: Sheck Wah Tong Printing Press.
Frame J, 2015. Trifolium incarnatum L. Grassland Species Profiles. Rome, Italy: FAO. http://www.fao.org/ag/agp/AGPC/doc/Gbase/data/pf000502.htm
Hackney B; Dear B; Crocker G, 2007. Naturalised pasture legumes. Primefacts No. 651. New South Wales, Australia: NSW Department of Primary Industries, 7 pp. http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0009/176688/Naturalised-pasture-legumes.pdf
Harshberger JW, 1922. Ecologic and morphologic study of the clovers (Trifolium). In: Proceedings of the American Philosophical Society, 61(2). 136-50.
Holl DK; Hayes GF, 2005. Challenges to introducing and managing disturbance regimes for Holocarpha macradenia, an endangered annual grassland forb. Conservation Biology, 20(4):1121-1131.
ILDIS, 2010. International Legume Database and Information Service: World Database of Legumes. Reading, UK: School of Plant Sciences, University of Reading. http://www.ildis.org/
Kamalak A; Canbolat O, 2010. Determination of nutritive value of wild narrow-leaved clover (Trifolium angustifolium) hay harvested at three maturity stages using chemical composition and in vitro gas production. Tropical Grasslands, 44:128-133. http://www.tropicalgrasslands.asn.au/Tropical%20Grasslands%20Journal%20archive/PDFs/Vol_44%20(1_2_3_4)/Vol%2044%20(2)%20Adem%20et%20al%20128.pdf
Lopez Poveda L, 2012. Trifolium angustifolium. T176423A20120853. The IUCN Red List of Threatened Species. http://dx.doi.org/10.2305/IUCN.UK.2012.RLTS.T176423A20120853.en
Manzano P; Malo JE, 2006. Extreme long-distance seed dispersal via sheep. Frontiers in Ecology and the Environment, 4(5):244-248.
Marticorena C; Quezada M, 1985. Gayana, Botánica, 42. 1-157.
McFadyen CR, 1998. Biological control of weeds. Annual Review of Entomology, 43:369-393.
Merou TP; Papanastasis VP, 2009. Factors affecting the establishment and growth of annual legumes in semi-arid Mediterranean grasslands. Plant Ecology, 201(2):491-500. http://springerlink.metapress.com/link.asp?id=100328
Muenscher WC, 1955. Weeds, 2nd edition. New York, USA: Macmillan, 560 pp.
Norman HC; Cocks PS; Galwey NW, 2005. Annual clovers (Trifolium spp.) have different reproductive strategies to achieve persistence in Mediterranean-type climates. Australian Journal of Agricultural Research, 56(1):33-43.
Osborne J, 2013. Trifolium angustifolium. e.T176423A7238416. The IUCN Red List of Threatened Species. http://www.iucnredlist.org/details/176423/1
Pereira C; Barros L; Carvalho AM; Ferreira ICFR, 2013. Use of UFLC-PDA for the analysis of organic acids in thirty-five species of food and medicinal plants. Food Analytical Methods, 6(5):1337-1344. http://rd.springer.com/article/10.1007/s12161-012-9548-6
Pérez-Fernández MA; Rodríguez-Echeverría S, 2003. Effect of smoke, charred wood, and nitrogenous compounds on seed germination of ten species from woodland in Central-Western Spain. Journal of Chemical Ecology, 29(1):237-251.
Rauter A; Palma FB; Justino J; Araújo ME; Santos SP, 2002. Natural Products in the new Millenium: Prospects and industrial application. Netherlands: Kluwer Academic publishers.
TERRAIN, 2015. Trifolium angustifolium. Taranaki Educational Resource: Research, Analysis and Information Network. New Zealand. http://www.terrain.net.nz/friends-of-te-henui-group/weeds-by-scientific-names/trifolium-angustifolium-narrow-leaved-clover.html
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
UC IPM, 2014. Pest in gardens and landscapes: Clovers. California, USA: University of California Agriculture and Natural Resources. http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7490.html
US Fish and Wildlife Service, 2014. Holocarpha macradenia (Santa Cruz tarplant). 5-Year Review: Summary and Evaluation. Ventura, California, USA: US Fish and Wildlife Service, 48 pp. http://ecos.fws.gov/docs/five_year_review/doc4365.pdf
USDA-ARS, 2016. Germplasm Resources Information Network (GRIN). National Plant Germplasm System. Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.aspx
USDA-NRCS, 2016. The PLANTS Database. Baton Rouge, USA: National Plant Data Center. http://plants.usda.gov/
Western Australian Herbarium, 2015. Trifolium angustifolium L. FloraBase - the Western Australian Flora. Western Australia: Department of Parks and Wildlife. https://florabase.dpaw.wa.gov.au/
Zohary M; Heller D, 1984. The genus Trifolium L. Jersusalem, Israel: The Israel Academy of Sciences and Humanities.
Auld B, Morita H, Nishida T, Ito M, Michael P, 2003. Shared exotica-plant invasions of Japan and south eastern Australia. Journal of Weed Science and Technology. 48 (3), 143-154. DOI:10.3719/weed.48.143
AVH, 2015. Australia's Virtual Herbarium., Canberra, ACT, Australia: Council of Heads of Australasian Herbaria. http://avh.chah.org.au/
CABI, Undated. Compendium record. Wallingford, UK: CABI
CABI, Undated a. CABI Compendium: Status inferred from regional distribution. Wallingford, UK: CABI
CABI, Undated b. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI
ILDIS, 2010. International Legume Database and Information Service: World Database of Legumes., Reading, UK: School of Plant Sciences, University of Reading. http://www.ildis.org/
Lopez Poveda L, 2012. Trifolium angustifolium. In: The IUCN Red List of Threatened Species, T176423A20120853. http://dx.doi.org/10.2305/IUCN.UK.2012.RLTS.T176423A20120853.en
Osborne J, 2013. (Trifolium angustifolium). In: The IUCN Red List of Threatened Species, http://www.iucnredlist.org/details/176423/1
USDA-ARS, 2016. 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, 2016. 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
Principal SourceTop of page
Draft datsheet under review
ContributorsTop of page
14/12/15 Original text by:
Fenadis Makale, CABI , UK
Distribution MapsTop of page
Select a dataset
CABI Summary Records
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/