Hardheads, Russian Knapweed, Turkestan Thistle: Acroptilon repens (Synonym: Centaurea repens) -
Blessed Thistle: Centaurea benedicta (Synonym: Cnicus benedictus) -
Purple Starthistle, Red Starthistle: Centaurea calcitrapa -
Bachelor's Button, Cornflower, Garden Cornflower: Centaurea cyanus -
Diffuse Knapweed, Tumble Knapweed, White Knapweed: Centaurea diffusa -
Iberian Knapweed, Iberian Starthistle: Centaurea iberica -
Brown Knapweed, Brownray Knapweed: Centaurea jacea (Synonyms: Centaurea jacea ssp. jacea, Centaurea jacea ssp. nigra) -
Bighead Knapweed, Globe Knapweed: Centaurea macrocephala -
Maltese Starthistle, Maltese Star-thistle, Tocalotes: Centaurea melitensis -
Meadow Knapweed, Protean Knapweed: Centaurea xmoncktonii -
Montane Starthistle, Mountain Bluet, Mountain Cornflower, Perennial Cornflower: Centaurea montana -
Black Knapweed, Hardheads, Lesser Knapweed: Centaurea nigra -
Short-fringed Knapweed, Tyrol Knapweed: Centaurea nigrescens (Synonyms: Centaurea dubia, Centaurea dubia ssp. nigrescens, Centaurea dubia ssp. vochinensis, Centaurea jacea ssp. nigrescens, Centaurea transalpina, Centaurea vochinensis) -
St. Barnaby's Thistle, Yellow Star-thistle, Yellow Star Thistle: Centaurea solstitialis -
Spotted Knapweed: Centaurea stoebe ssp. australis (Synonyms: Centaurea maculosa, Centaurea stoebe ssp. micranthos) -
Hybrid Knapweed, Meadow Knapweed, Protean Knapweed: Centaurea xgerstlaueri (Synonyms: Centaurea debeauxii ssp. thuillieri, Centaurea xmoncktonii, Centaurea nigra x Centaurea jacea, Centaurea x pratensis) -
Klein's Knapweed: Centaurea xkleinii -
Diffuse-spotted Knapweed: Centaurea xpsammogena -
Hybrid Diffuse Knapweed, Sand Knapweed: Centaurea xvarnensis -