Compilation
Centaurea thuillieri

Perennials, 30–150 cm. Stems 1–few, erect or ascending, openly branched distally, villous to scabrous with septate hairs and loosely tomentose, ± glabrate. Leaves: basal and proximal cauline petiolate, blades oblanceolate or elliptic, 5–25 cm, margins entire or shallowly dentate to irregularly pinnately lobed; distal cauline sessile, not decurrent, blades linear to lanceolate, gradually smaller, entire or dentate. Heads usually radiant (rarely discoid), in few-headed corymbiform arrays, borne on leafy-bracted peduncles. Involucres ovoid to campanulate or hemispheric, 15–l8 mm, usually ± as wide as high. Principal phyllaries: bodies lanceolate to ovate, loosely tomentose or glabrous, usually concealed by expanded appendages, appendages erect, overlapping, light to dark brown, flat or ± concave, margins varying from coarsely dentate to pectinately dissected into ± wiry lobes. Inner phyllaries: tips truncate, irregularly dentate or lobed. Florets 40–100+, all fertile or the peripheral sterile; corollas purple (rarely white), those of sterile florets ± expanded and exceeding corollas of fertile florets, those of fertile florets 15–18 mm. Cypselae tan, 2.5–3 mm, finely hairy; pappi 0 or of many unequal, sometimes caducous bristles 0.5–1 mm. 2n = 22 (England), 44.