Centaurea calcitrapa
Centaurea calcitrapa 001.jpg
Young plant
Scientific classification edit
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Asterales
Family: Asteraceae
Genus: Centaurea
C. calcitrapa
Binomial name
Centaurea calcitrapa

Centaurea calcitrapa is a species of flowering plant known by several common names, including red star-thistle[1] and purple starthistle. It is native to Europe but is rarely found there, it is known across the globe as an introduced species and often a noxious weed.[2][3] The species name calcitrapa comes from the word caltrop, a type of weapon covered in sharp spikes.[4][5]


This an annual or biennial plant growing erect to a maximum height of one[6] to 1.3[4] metres.

The stems are hairless and grooved.[7]

It sometimes takes the shape of a mound, and it is finely to densely hairy to spiny. The leaves are dotted with resin glands. The lowermost may reach a length of 20 centimeters and are deeply cut into lobes. The inflorescence contains a few flower heads. Each is 1.5 to 2 centimeters long and oval in general shape. The phyllaries are green or straw-colored and tipped in tough, sharp yellow spines. The head contains many bright purple flowers. The fruit is an achene a few millimeters long which lacks a pappus.

It flowers from July until September, and the seeds ripen from August to October.

The Red Star-thistle has been identified as a Priority Species by the UK Biodiversity Action Plan. It is identified as 'vulnerable' by the UNIC and is listed as Nationally Rare in the UK Red Data Book. There is no national or Sussex BAP for this species.



Native distribution

  • In France

Introduced distribution

  • In Australia


In western Crete, Greece a local variety called gourounaki (γουρουνάκι - little pig) has its leaves eaten boiled by the locals.[9] A south Italian variety of the species is also traditionally consumed by ethnic Albanians (Arbëreshë people) in the Vulture area (southern Italy). In the Arbëreshë communities in Lucania the young whorls of Centaurea calcitrapa are boiled and fried in mixtures with other weedy non cultivated greens.[10]



Picloram + 2,4-D, low volatile ester 2,4-D, Dicamba, and Fluroxypyr + Aminopyralid are recommended for use in New South Wales,[11] and aminocyclopyrachlor + chlorsulfuron, aminopyralid, chlorsulfuron, clopyralid, clopyralid + 2,4-D, dicamba, diflufenzopyr + dicamba, picloram, and triclopyr + clopyralid for the Pacific Northwest of North America.[12]

Herbicide resistance

Picloram + 2,4-D, low volatile ester 2,4-D, Dicamba, and Fluroxypyr + Aminopyralid all carry a "moderate" risk of producing resistance in C. calcitrapa.[11]

Similar species

  • Centaurea aspera, known as rough star-thistle. The main difference is the bract appendages are palmately arranged.
  • Centaurea solstitialis, known as yellow star thistle. Differs in having yellow flowers palmately arranged, spiny bract appendages, with middle spine only 1 to 2 cm.


  1. ^ BSBI List 2007 (xls). Botanical Society of Britain and Ireland. Archived from the original (xls) on 2015-06-26. Retrieved 2014-10-17.
  2. ^ "Centaurea calcitrapa". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 24 July 2012.
  3. ^ "Centaurea genus part 1". California Department of Food and Agriculture. Archived from the original on 12 December 2012. Retrieved 24 July 2012.
  4. ^ a b "University of California Cooperative Extension". Ucce.ucdavis.edu. Retrieved 2013-01-14.
  5. ^ Pitcairn, Michael J.; Young, James A.; Clements, Charlie D.; Balciunas, JOE (2002). "Purple Starthistle (Centaurea calcitrapa) Seed Germination1". Weed Technology. 16 (2): 452. doi:10.1614/0890-037X(2002)016[0452:PSCCSG]2.0.CO;2. ISSN 0890-037X.
  6. ^ "Jepson Manual Treatment". Ucjeps.berkeley.edu. Retrieved 2013-01-14.
  7. ^ Rose, Francis (1981). The Wild Flower Key. Frederick Warne & Co. pp. 386–387. ISBN 0-7232-2419-6.
  8. ^ "Centaurea calcitrapa L. - Plants of the World Online". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2021-03-03.
  9. ^ Κλεόνικος Γ. Σταυριδάκης [Kleonikos G. Stavridakis] (2006). Η Άγρια βρώσιμη χλωρίδα της Κρήτης [Wild edible plants of Crete]. Rethymnon Crete. ISBN 960-631-179-1.CS1 maint: extra punctuation (link) CS1 maint: multiple names: authors list (link)
  10. ^ A. Pieroni, V. Janiak, C. M. Dürr, S. Lüdeke, E. Trachsel and M. Heinrich: In vitro Antioxidant Activity of Non-cultivated Vegetables of Ethnic Albanians in Southern Italy, Centre for Pharmacognosy and Phytotherapy, The School of Pharmacy, University of London 29-39 Brunswick Square, London WC1N 1AX, UK; PHYTOTHERAPY RESEARCH, 16, 467–473 (2002) Archived July 18, 2011, at the Wayback Machine
  11. ^ a b "Star thistle (Centaurea calcitrapa)". NSW WeedWise, Department of Primary Industries, New South Wales, Australia. Retrieved 2021-03-03.
  12. ^ "Starthistle, yellow (Centaurea solstitialis), purple (Centaurea calcitrapa), and Iberian (Centaurea iberica)". Pacific Northwest Pest Management Handbooks. Pacific Northwest Extension (Oregon, Washington, Idaho). 2015-11-10. Retrieved 2021-03-03.

External links