Centaurea cyanus Linnaeus

Centaurea cyanus is a commonly cultivated garden ornamental. Its cypselae are often included in wildflower seed mixes and it naturalizes readily in many areas.

Annuals, 20–100 cm. Stems usually 1, erect, ± openly branched distally, loosely tomentose. Leaves ± loosely gray-tomentose; basal leaf blades linear-lanceolate, 3–10 cm, margins entire or with remote linear lobes, apices acute; cauline linear, usually not much smaller except among heads, usually entire. Heads radiant, in open, rounded or ± flat-topped cymiform arrays, pedunculate. Involucres campanulate, 12–16 mm. Phyllaries: bodies green, ovate (outer) to oblong (inner), tomentose or becoming glabrous, margins and erect appendages white to dark brown or black, scarious, fringed with slender teeth ± 1 mm. Florets 25–35; corollas blue (white to purple), those of sterile florets raylike, enlarged, 20–25 mm, those of fertile florets 10–15 mm. Cypselae stramineous or pale blue, 4–5 mm, finely hairy; pappi of many unequal stiff bristles, 2–4 mm. 2n = 24 (Russia).

Native of the Mediterranean region and Europe, widely cultivated elsewhere and a weed.

3700 m

Leucacantha cyanus (Linnaeus) Nieuwland & Lunell