Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide


Centaurea melitensis
(Maltese starthistle)



Centaurea melitensis (Maltese starthistle)


  • Last modified
  • 26 April 2019
  • Datasheet Type(s)
  • Invasive Species
  • Preferred Scientific Name
  • Centaurea melitensis
  • Preferred Common Name
  • Maltese starthistle
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Plantae
  •     Phylum: Spermatophyta
  •       Subphylum: Angiospermae
  •         Class: Dicotyledonae
  • Summary of Invasiveness
  • C. melitensis is native to northern Africa and southern Europe in the western Mediterranean region, and has successfully invaded similar climates in the USA, New Zealand, Australia and South America. In favoura...

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Centaurea melitensis; flowering head.
CaptionCentaurea melitensis; flowering head.
Copyright©Cindy Roché
Centaurea melitensis; flowering head.
FlowerCentaurea melitensis; flowering head.©Cindy Roché


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Preferred Scientific Name

  • Centaurea melitensis Linnaeus, 1753

Preferred Common Name

  • Maltese starthistle

Other Scientific Names

  • Calcitrapa patibilcensis Kunth, 1818

International Common Names

  • English: Malta starthistle; Maltese cockspur; Maltese star centaury; Maltese star-thistle; Maltese thistle; Napa starthistle; Napa thistle

Local Common Names

  • Brazil: centáurea-estrela-de-Malta
  • France: coix de Malte
  • Germany: Malteser Flockenblume
  • Spain: cardo escarolado; yerba de cristo
  • USA: tocalote; tocolote

Summary of Invasiveness

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C. melitensis is native to northern Africa and southern Europe in the western Mediterranean region, and has successfully invaded similar climates in the USA, New Zealand, Australia and South America. In favourable habitats it can form dense stands that replace native and desirable vegetation. It is commonly less aggressive than Centaurea solstitialis and in some areas grows as a minor forb in annual grasslands. C. melitensis usually invades open, disturbed sites and is often spread by humans and livestock and by transportation of contaminated soil, crop seed or hay (DiTomaso and Healy, 2007).

Taxonomic Tree

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  • Domain: Eukaryota
  •     Kingdom: Plantae
  •         Phylum: Spermatophyta
  •             Subphylum: Angiospermae
  •                 Class: Dicotyledonae
  •                     Order: Asterales
  •                         Family: Asteraceae
  •                             Genus: Centaurea
  •                                 Species: Centaurea melitensis

Notes on Taxonomy and Nomenclature

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The synonym Calcitrapa patibilcensis Kunth (published in 1818) was used in a checklist prepared by Hind and Jeffrey (2001). It is not in common use. Centaurea melitensis is the commonly accepted name.


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Adapted primarily from Keil and Ochsmann (2006) and DiTomaso and Healy (2007):

Erect plants 10-100 cm tall, herbage grey-green loosely tomentose and villous with jointed multicellular hairs, sometimes minutely scabrous. Leaves dotted with minute resinous glands. Stems single or several with few to many distal branches. Basal and proximal cauline leaves petiolate or tapering to the base, usually absent by anthesis, blades oblong to oblanceolate, 2-15 cm, margins entire to dentate or pinnately lobed. Cauline leaves long, decurrent, forming wings up to 3 mm wide down the stems, blades linear to oblong or oblanceolate, 1-5 cm long, margins entire or dentate. Young leaves sometimes densely covered with fine, cottony hairs, which become sparse with age and no longer hide the stiff hairs and resinous dots. Heads round to ovoid, solitary or in close corymbiform clusters of 2-3 at the tips of stems, sometimes clustered in distal axils, sessile or pedunculate; all disc flowers. Corollas yellow, typically 10-12 mm long. Involucres 8-15 mm, loosely cobwebby-tomentose or becoming glabrous. Central spine of principal phyllaries 5-12 mm long, slender, often purple to brown tinged, with lateral spines in 3 to 4 pairs, the upper pair near the middle of the central spine. Inner phyllary appendages entire, acute or spine-tipped. Three types of capitula are produced: cross-pollinating heads with fully expanded flowers, and two cleistogamous (self-pollinating) types, one with yellow flowers only partially protruding and one without exserted corollas. Three types of achenes are produced, with the variation linked to capitulum type: initial cleistogamous capitula produce thick achenes bearing a short pappus; in final cleistogamous capitula achenes are small with a short pappus; and chasmogamous (outcrossing) capitula produce small achenes with a longer pappus (Porras and Muñoz, 2000). Most achenes are 2-3 mm long, finely pubescent, greyish to tan, usually with slightly darker stripes. The base is deeply notched, narrow, hook-like. Pappus bristles are pale tan, 1-3 mm long.

Seedling identification: Cotyledons oblong to spatulate, base wedge-shaped, tip truncate to slightly rounded, glabrous. First few true leaves typically oblanceolate. Later rosette leaves entire to deeply lobed, nearly to the midvein, lobes usually rounded, including the terminal one. Upper and lower surfaces evenly covered with stiff, thick hairs and resinous glands. Fine, cottony hairs dense on young leaves becoming sparse on older leaves (DiTomaso and Healy, 2007).

Plant Type

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Seed propagated

Distribution Table

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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/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes


ChinaPresentIntroducedAnonymous, 1986
TurkeyAbsent, formerly presentIntroduced Not invasive Wagenitz, 1975Casual introduction to Rodhos


AlgeriaPresentNative Not invasive ISSG, 2009
AngolaPresentIntroducedJeffrey, 1968
EthiopiaPresentIntroducedJeffrey, 1968
KenyaPresentIntroducedJeffrey, 1968
LibyaPresentNative Not invasive Ali and Jafri, 1976NW region of country
MoroccoPresentNative Not invasive Garcia-Jacas et al., 2006
South AfricaPresentIntroducedRussell et al., 1987
-Canary IslandsPresentNative Not invasive Izquierdo et al., 2004On these islands: El Hierro, La Palma, Tenerife, Gran Canaria, Fuerte Ventura, Lanzarote
TunisiaPresentNative Not invasive Pottier-Alapetite, 1979-1981
ZimbabwePresentIntroducedJeffrey, 1968

North America

CanadaPresentPresent based on regional distribution.
-British ColumbiaPresentIntroduced Not invasive Roché and Roché, 1991; Brouillet et al., 2006Georgeson & Samuel Islands, 1980
MexicoPresentIntroduced Invasive CONABIO, 2009Established
USAPresentPresent based on regional distribution.
-AlabamaAbsent, formerly presentIntroduced1901 Not invasive Mohr, 1901; USDA-NRCS, 2009Mobile Co. “fugitive on ballast”
-ArizonaPresentIntroduced2009 Invasive USDA-NRCS, 2009Apache, Cochise, Graham, Maricopa, Mohave, Pima, Pinal, and Yavapai counties; Tonto and Coconino National Forests. Not as aggressive as C. solstitialis, it readily infests disturbed roadsides and is especially problematic in and around the city of Tucson and along roadsides in the Sonoran desert.
-CaliforniaWidespreadIntroduced2009 Invasive DiTomaso and Healy, 2007; USDA-NRCS, 2009Throughout most of California, except Great Basin region, to 2200 m. Common in the central-western and south-western regions
-GeorgiaPresentIntroduced Not invasive Duncan and Kartesz, 1981Probably not persisting
-HawaiiPresentIntroduced Invasive Wagner et al., 1999Hawai’i, Moloka’i, Maui, Kaho‘olawe, Kaua’i, Lana‘i, Ni‘ihau Islands
-IdahoUnconfirmed recordIntroduced Not invasive Keil and Ochsmann, 2006Not shown in other sources
-IndianaPresentIntroduced Not invasive USDA-NRCS, 2009Undocumented report
-MassachusettsPresentIntroduced Not invasive Magee, 1940Probably non-persisting, casual introduction
-MissouriPresentIntroduced Not invasive Yatskievych and Turner, 1990; Weber and Corcoran, 1993
-NevadaLocalisedIntroduced Invasive USDA-NRCS, 2009On state noxious weed list; found in Clark & Nye counties
-New MexicoPresentIntroduced Invasive USDA-NRCS, 2009Class B noxious weed. Found in Hidalgo, Grant, Luna, Dona Ana, Otero, Chaves & Eddy counties
-OregonLocalised2005Introduced1876 Invasive Roché and Talbott, 1986Reported from Josephine (1886-2005), Douglas (1887-2003), Hood River (1884), Jackson (1896, 1927), Multnomah (1910), Marion (1911), Benton (1918), Curry (1919, 1925, 1947), Coos (1926), Linn (1931), Lane (1934) counties. Widely introduced along the coast and inland valley, but only persistent in the Mediterranean climate of the southwestern part of the state
-PennsylvaniaPresentIntroduced Not invasive Wherry et al., 1979Probably a casual introduction, non-persisting, see also Rhoads & MacKinley (1993)
-South CarolinaPresentIntroduced Not invasive Nesom, 2004Cleaned from fleeces at woolen mill in Berkeley Co. documented in 1957, 1958
-TexasPresentIntroduced Invasive USDA-NRCS, 2009Numerous counties in west Texas, a few in central Texas
-UtahPresentIntroduced Not invasive USDA-NRCS, 2009Disturbed sites in Salt Lake & Washington counties
-WashingtonPresent, few occurrences1985Introduced1897 Not invasive Burke Museum of Natural History and Culture, 2006Historic records in Clallam, Island and Whatcom counties, current site in Klickitat Co.
-WisconsinPresent Not invasive USDA-NRCS, 2009Probably a casual, not persisting introduction

South America

ArgentinaPresentIntroduced Invasive Nobile and Luján, 1989Agricultural weed
ChilePresentIntroducedMarticorena and Quezada, 1985; Negrete et al., 1989; Finot et al., 1996Common, weed of southcentral Chile
EcuadorPresentIntroducedJorgensen and Ulloa, 1994; Jørgensen and León-Yànez, 1999Pichincha Province
PeruPresentIntroducedDillon, 1982Andean I-II, Coastal: disturbed areas. Ancash, Cuzco, Junín, La Libertad dpts


FrancePresentNative Not invasive Guinochet and Vilmorin, 1987Mainly in the south
-CorsicaPresentNative Not invasive Guinochet and Vilmorin, 1987
GreecePresentNative Not invasive Dostal, 1976
ItalyPresentNative Not invasive Pignatti, 1982Lig. Occid. In Riviera, Lazio al Circeo, Puglie, Cal,, Sic., Sard., Cors., Guanutri ed Is. Maltesi
PortugalPresentNative Not invasive Dostal, 1976
-AzoresPresentNative Not invasive Silva et al., 2005On these islands: Faial, Pico, Graciosa, Sao Jorge, Santa Maria
SpainWidespreadNative Not invasive Dostal, 1976; Flora de Aragón, 2009
UKPresentIntroducedDunn, 1905Frequently introduced with grain to fields
Yugoslavia (former)PresentNative Not invasive Dostal, 1976


AustraliaPresentPresent based on regional distribution.
-New South WalesAbsent, formerly presentIntroduced Invasive Orchard, 1994"A weed of waste places. A.N. Rodd & J. Pickard, Cunninghamia 1: 278 (1983) suggested that it was only established briefly on Lord Howe Is. and has since died out". Voucher cited: J.D McComish 206 (NSW)
-Western AustraliaPresentIntroduced<1897 Invasive Lindley-Cowan, 1897; Spooner, 1997Weed of roadsides, cultivated areas & other disturbed areas. Distribution: ER: CAR, COO, HAM, MUR, NUL, YAL; SW: AW, ESP, GS, JF, MAL, SWA, WAR
New CaledoniaPresentIntroduced Invasive MacKee, 1994; Tassin, 2005Isle Grande Terre, Vouchers cited: Deplanche 226 s.loc., Cribs 949, Schlechter 15024
New ZealandPresentIntroduced1891Healey, 19442009 adventive, invasive status not yet classified. In 1944 thoroughly established on the bluffs of Hurunui River; well dispersed in modified tussock grassland, Mt. Benger Station, Mt. Alexander Station, and Hitchen Hills, North Canterbury
Norfolk IslandPresentIntroduced1902 Invasive Orchard, 1994"A weed of waste places". Vouchers cited: W.R. Sykes NI 975 (CHR); 1902, J.H. Maiden & J.L. Boorman (NSW)

History of Introduction and Spread

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C. melitensis was widely distributed throughout the 1700s and 1800s, during the period of worldwide colonization by Spain and Portugal; its seeds were carried in the soil used as ship ballast, lodged in the wool of sheep, and as a contaminant of cereal grains, either in seed or straw (Roché and Talbott, 1986). It was probably introduced in California, USA, in the late 1700s during the Spanish missionary period (Spira and Wagner, 1983; DiTomaso and Healy, 2007). It reached South America, Hawaii, Australia and New Zealand during the same era. It failed to establish in northern and eastern US states, despite numerous introductions. In California, C. melitensis has been more invasive in the west-central and south-western regions, as well as across southern Arizona, New Mexico and western Texas. It forms the dominant vegetation in some California inland valley and foothill annual grasslands (Borchert and Jain, 1978).


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C. melitensis invades open, disturbed sites (including waste areas and roadsides), open (oak) woodlands, rangelands and natural grasslands (both annual and perennial), non-irrigated pastures and cultivated fields (Roché et al., 1986; DiTomaso and Healy, 2007). The altitudinal range in California is from sea level to 2200 m and it is uncommon in desert regions (DiTomaso and Healy, 2007). Historically, before the use of broadleaf herbicides was common practice, it was a significant pest in grain fields (Lindley-Cowan, 1897; Dunn, 1905; Roché et al., 1986). It has been reported growing in beach sand along the Pacific coast of North America (Roché and Talbott, 1986). Keil and Ochsmann (2006) also reported it in pine-oak woodlands and chaparral from sea level to 1500 m altitude. In Aragón, Spain, habitats are listed as dry pastures, uncultivated land, roadsides and ditch banks, between 70 and 1200 m; flora fields where C. melitensis grows are subnitrophilous pioneer pasture communities that are subject to frequent disturbance (unstable).

In West Yorkshire, UK, Shimwell (2006) reported that some weeds introduced with wool waste became ‘casuals’, not persisting for more than a few years. Many casuals of the Cardueae Tribe of the Asteraceae (including C. melitensis) appear to have suffered due to the progressive reduction in marginal habitats on natural soils and in their inability to withstand competition from gregarious weed species. An increase in a highly competitive nitrophilous weed flora thus appears to have further restricted the frequency of opportunity for annual and biennial wool aliens typical of relatively xeric soil conditions.

Habitat List

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Terrestrial – ManagedCultivated / agricultural land Present, no further details
Terrestrial ‑ Natural / Semi-naturalNatural grasslands Principal habitat Harmful (pest or invasive)
Scrub / shrublands Secondary/tolerated habitat Harmful (pest or invasive)

Biology and Ecology

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Reproductive Biology

C. melitensis
reproduces solely by seed. Plants characteristically have both outcrossing and cleistogamous capitula, an adaptation that ensures seed production in risky conditions (Porras and Muñoz, 2000). Flowering culms develop in early spring. Seed production is highly variable, ranging from one to 60 seeds per head and one to more than 100 heads per plant, depending on the availability of resources (DiTomaso and Healy, 2007). The litter of Avena fatua appears to have allelopathic properties which reduce the germination of C. melitensis seeds (Tinnin and Muller, 1972).

Physiology and Phenology

Most seeds germinate after the first autumn rains. Plants remain as rosettes while growing deep tap roots throughout the winter and early spring. The taproots of C. melitensis do not usually penetrate as deeply in the soil as those of C. solstitialis, so plants flower much earlier in the growing season (DiTomaso and Healy, 2007). Depending on altitude and latitude, flowering occurs from April through July (Keil and Ochsmann, 2006).
In a comparison of C. melitensis with the more aggressive C. solstitialis, Gerlach and Rice (2003) found minimal differences in seed germination responses and seedling establishment and survival, but differential growth responses to different sizes of canopy gaps led to large differences in adult size and fecundity. Canopy-gap size and clipping affected the fecundity of each species, but the most invasive species (C. solstitialis) was unique in its strong positive response to combinations of clipping and canopy gaps. In addition, C. solstitialis extended its growing season into the summer, which C. melitensis, with its shallower roots, cannot do. The results suggest that C. melitensis is less invasive than C. solstitialis because, in part, it is less competitive with annual grasses and less plastic in its growth and fecundity responses to open, disturbed habitat patches.


In a study of the relationship of soil fungi and native bunchgrass to C. melitensis competitiveness, Callaway et al. (2001) found that the biomass of clipped C. melitensis grown with both Nassella pulchra and non-treated soil fungi was equal to that of unclipped plants. When stressed by defoliation, C. melitensis benefited from mycorrhizae or N. pulchra altered the fungal community to enhance the positive direct effects of soil fungi on C. melitensis.

Environmental Requirements

Milberg et al. (1999) grew C. melitensis in a study comparing survival and growth of exotic and native species along a nutrient gradient in Western Australia and found that the exotic species responded more positively to higher nutrient additions than the native species, indicating that the exotics might have a competitive advantage in a nutrient-enhanced situation (e.g., after fire). During monitoring of response of C. melitensis populations after a wildfire in California, its population expanded beyond pre-fire levels from 2004-2005, but declined in frequency during 2006, probably because of reduced rainfall during the third year (Hubbert, 2007).


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BS - Steppe climate Tolerated > 430mm and < 860mm annual precipitation
Cf - Warm temperate climate, wet all year Preferred Warm average temp. > 10°C, Cold average temp. > 0°C, wet all year

Soil Tolerances

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Soil drainage

  • free

Soil texture

  • light
  • medium

Special soil tolerances

  • infertile
  • shallow

Means of Movement and Dispersal

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Natural Dispersal (Non-Biotic)

Most seeds fall near the parent plant or is dispersed over short distances by wind or sometimes water (DiTomaso and Healy, 2007).

Vector Transmission (Biotic)

Longer distance dispersal is usually mediated by human or other animal activities such as being carried on vehicles, transported in mud or soil, on hooves or equipment, clinging to fur or hair, or passing through a digestive tract of an animal. In Chile, researchers found 32% germination of C. melitensis seeds distributed in rabbit faeces (Fernandez and Saiz, 2007), indicating that European rabbits were vectors. The presence of C. melitensis seeds in fleeces cleaned at woollen mills indicates that sheep transport the seeds (Nesom, 2004).

Accidental Introduction

All of the introductions appear to have been accidental, or at least caused by carelessness. Soil carried as ballast on ships appears to have been the most significant long distance dispersal mechanism between continents (Roché and Talbott, 1986). Movement with cereal grains probably also contributed (Dunn, 1905).

Impact Summary

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Economic/livelihood Negative
Environment (generally) Negative

Environmental Impact

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Impact on Habitats

The Forest Service included C. melitensis in the list of the invasive, non-native species posing the greatest threat to successful restoration of native vegetation in chaparral types following the 2003 Grand Prix/Old Fire in the San Bernardino Mountains of southern California (Hubbert, 2007).

After the fires, surveys for infestations of the target weed species found that C. melitensis covered large acreages. Fire disturbance aided the spread of weed infestations that were already present before the fire, either in the seed bank or in close proximity to the burn, including infestations of C. melitensis which expanded beyond the pre-fire levels, especially on fire roads. It was probably already established along roadsides before the fire, but was able to spread into new areas because of a lack of competition after the fire. Dozer lines, safety zones and hand lines were the second most infested areas and, in most cases, C. melitensis grew faster than the native species (Hubbert, 2007).

Impact on Biodiversity

The Forest Service is monitoring the expansion of a population of C. melitensis following the Cedar Fire in southern California chaparral and its potential impact on the habitat of the listed species Acanthomintia ilicifolia on Viejas Mountain (Hubbert, 2007).

Threatened Species

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Threatened SpeciesConservation StatusWhere ThreatenedMechanismReferencesNotes
Acanthomintha ilicifoliaNatureServe NatureServe; USA ESA listing as threatened species USA ESA listing as threatened speciesCaliforniaCompetition - monopolizing resourcesUS Fish and Wildlife Service, 2009a
Cirsium wrightii (Wright's marsh thistle)NatureServe NatureServe; USA ESA candidate species USA ESA candidate speciesArizona; New MexicoCompetition (unspecified); Ecosystem change / habitat alterationUS Fish and Wildlife Service, 2015
Enceliopsis nudicaulis var. corrugata (Ash Meadows sunray)USA ESA listing as threatened species USA ESA listing as threatened speciesCalifornia; NevadaCompetition - monopolizing resources; Ecosystem change / habitat alterationUS Fish and Wildlife Service, 2011
Grindelia fraxinipratensis (ash meadows gumplant)NatureServe NatureServe; USA ESA listing as threatened species USA ESA listing as threatened speciesCalifornia; NevadaCompetition - monopolizing resourcesUS Fish and Wildlife Service, 2007
Zeltnera namophilaNo DetailsCalifornia; NevadaCompetition - monopolizing resourcesUS Fish and Wildlife Service, 2009b

Risk and Impact Factors

Top of page Invasiveness
  • Proved invasive outside its native range
  • Abundant in its native range
  • Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
  • Pioneering in disturbed areas
  • 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
  • Reproduces asexually
Impact outcomes
  • Ecosystem change/ habitat alteration
  • Modification of successional patterns
  • Negatively impacts agriculture
  • Negatively impacts animal health
  • Negatively impacts livelihoods
  • Reduced native biodiversity
  • Threat to/ loss of native species
Impact mechanisms
  • Competition - monopolizing resources
  • Competition
  • Rooting
  • Produces spines, thorns or burrs
Likelihood of entry/control
  • Highly likely to be transported internationally accidentally
  • Difficult to identify/detect as a commodity contaminant
  • Difficult to identify/detect in the field


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Economic Value

C. melitensis is used in Spain for its stomachic, diuretic and hypoglycaemic properties (Negrete et al., 1989).

Uses List

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Human food and beverage

  • Honey/honey flora

Medicinal, pharmaceutical

  • Source of medicine/pharmaceutical

Similarities to Other Species/Conditions

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C. melitensis and C. solstitialis might be confused by someone unfamiliar with both species. Both are winter annuals that invade similar habitats and have spiny phyllaries and yellow flowers. The central spines of C. melitensis are shorter (5-12 mm) than those of C. solstitialis (10-25 mm) and are branched closer to the tip. They are purplish to brown-tinged compared with the yellowish to straw-coloured spines of C. solstitialis. The senescent flower heads of C. melitensis retain the spined phyllaries and shed the fuzzy centre (leaving an empty ‘bowl’), whereas those of C. solstitialis shed the spined bracts and retain the fuzzy centre (leaving a cottony tip) (DiTomaso and Healy, 2007).

Prevention and Control

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Biological control

A small beetle (Lasioderma haemorrhoidale) that feeds in the capitula of C. melitensis was unintentionally introduced in California from the Mediterranean region, but has had little impact on controlling C. melitensis populations (DiTomaso and Healy, 2007). It is a generalist seed feeder that also attacks C. solstitialis, C. sulphurea and Carduus pycnocephalus. Two other agents introduced for C. solstitialis, Chaetorellia succinea and Eustenopus villosus, also utilize C. melitensis, but to a lesser extent (DiTomaso and Healey, 2007). In host specificity tests, there was significant larval development by the Eurasian weevil Ceratapion basicorne on C. melitensis (Smith, 2007).

Chemical control

C. melitensis is susceptible to the same chemicals as other Centaurea species, including phenoxy acetic acid (2,4-D), benzoic acid (dicamba), pyridines (triclopyr, aminopyralid, clopyralid, picloram), imidazolinones (imazapic), semicarbazone (diflufenzopyr) and glyphosate. Recommended rates and application times for the Pacific Northwest states are given in Peachey (2009).

Control by utilization

Cattle may graze C. melitensis if adequate palatable forage is lacking, but the amount of use under normal conditions is probably minimal. Sheep and goats would probably be more effective, but have not been studied. They could also contribute to spread of the weed.

Ecosystem Restoration

In an experiment in the Sequoia National Park, California, USA, annual grasslands dominated by exotic annuals were burned once in the spring or autumn or in two or three successive years in the spring or autumn to convert them to native perennial bunchgrasses. Both burning regimes increased the number of alien and native forb species without establishing any native grass. C. melitensis, which was not encountered in any plots before burning, accounted for most of the alien forb response (Parsons and Stohlgren, 1989). DiTomaso et al. (2001) burned for 2 consecutive years in the late spring or early summer for control of barb goatgrass (Aegilops triancialis) and noted a decrease in the frequency of C. melitensis on annual grassland in California.


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Links to Websites

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Biodiversity Heritage Library
GISD/IASPMR: Invasive Alien Species Pathway Management Resource and DAISIE European Invasive Alien Species Gateway source for updated system data added to species habitat list.
Global register of Introduced and Invasive species (GRIIS) source for updated system data added to species habitat list.
New Zealand Plant Conservation Network
Pacific Island Ecosystems at Risk (PIER)


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13/11/09 Original text by:

Dominique Roche, McGill University - STRI, Department of Biology, Canada

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