Annuals, 10-100 cm, herbage loosely gray-tomentose and villous with jointed multicellular hairs, sometimes minutely scabrous, minutely resin-gland-dotted. Stems 1-few, few-many branched distally. Leaves: basal and proximal cauline petiolate or tapering to base, usually absent at anthesis, blades oblong to oblanceolate, 2-15 cm, margins entire to dentate or pinnately lobed; cauline long-decurrent, blades linear to oblong or oblanceolate, 1-5 cm, entire or dentate. Heads disciform, 1-few at branch tips, borne singly or in open leafy corymbiform arrays, sometimes clustered in distal axils, sessile or pedunculate. Involucres ovoid, 10-15 mm, loosely cobwebby-tomentose or becoming glabrous. Principal phyllaries: bodies ± stramineous, ovate, appendages purplish, spiny-fringed at base, each tipped by slender spine 5-10 mm. Inner phyllaries: appendages entire, acute or spine-tipped. Florets many; corollas yellow, those of sterile florets 10-12 mm, slender, inconspicuous, those of fertile florets 10-12 mm. Cypselae dull white or light brown, ca. 2.5 mm, finely hairy; pappi of many white, unequal, stiff bristles 2.5-3 mm. 2n = 24. Flowering mostly spring-summer (Apr-Jul). Roadsides, fields, pine-oak woodlands, chaparral, agricultural areas; 0-1500 m; widely introduced; B.C.; Ala., Ariz., Calif., Ga., Idaho, Ill., Mass., Miss., Mo., Nev., N.J., N.Mex., Oreg., Pa., Tex., Utah, Wash., Wis.; Mexico (Baja California); Europe; Asia; Africa. Centaurea melitensis is native to the Mediterranean region. It is listed as a noxious weed in New Mexico.

Plant: Annual forb to 90 cm; branches winged, with cottony pubescence Leaves: leaves alternate, basal leaves deeply lobed, upper leaves entire, narrow to a sessile base; cauline long-decurrent INFLORESCENCE: primary inflorescence a head, each resembling a flower; heads 1-few; involucre 10-15 mm, ovoid, ± cobwebby or becoming glabrous; main phyllaries ± straw-colored, appendage purplish, base spine-fringed, central spine 5-10 mm, slender Flowers: many; inner fruiting; corollas 10-12 mm, ± equal, yellow, sterile corollas slender; anther bases tailed, tips oblong; style top minutely hairy, tips minutely branched Fruit: ± 2.5 mm, ± light brown, finely hairy, ± barrel-shaped, ± compressed, attached ± at side; pappus bristles 2.5-3 mm, white Misc: Disturbed fields, open woods; < 2200 m.; May-Jun Notes: spines of phyllaries purplish References: Arizona Flora, Jepson Manual, ASU specimens