Carduus tenuiflorus, known variously as slender-flower thistle, sheep thistle, shore thistle, slender thistle, winged plumeless thistle, winged slender thistle and winged thistle, is a species of flowering plant in the family Asteraceae. It is native to Europe and North Africa, and an introduced species elsewhere. Description Carduus tenuiflorus may exceed in height. Its tall stem is ridged with wings and has long spines which may be several centimeters in length. The dull olive-green leaves are lobed and wrinkled and may fold and crease themselves. The inflorescences may hold up to 20 flower heads which are somewhat rounded, covered in wide, spiny phyllaries, and packed with pale pink to bright purple long-tubed disc florets. This is a tenacious weed of roadsides, fields, and disturbed areas. Distribution Carduus tenuiflorus is native to western North Africa in: northern Algeria; Morocco; and Tunisia, and much of Europe in: Belgium; France, including Corsica; Ireland; Italy, including Sardinia and Sicily; the Netherlands; Portugal, Spain, including the Baleares (Balearic Islands); and the United Kingdom. Introduced species It has become naturalised in Macaronesia, South Africa, India, Australasia, Southern South America, regions of the United States, and elsewhere. It is an invasive species in California. References External links Jepson Manual Treatment Carduus tenuiflorus — CalPhoto gallery tenuiflorus Flora of Europe Flora of North Africa Plants described in 1793 Flora of Algeria Flora of Belgium Flora of Corsica Flora of Ireland Flora of Italy Flora of Sardinia Flora of Sicily Flora of Morocco Flora of the Netherlands Flora of Portugal Flora of Spain Flora of the Balearic Islands Flora of Tunisia Flora of the United Kingdom