Cyanus Miller (1754: 4)

Negaresh, Kazem, 2022, A checklist of the genus Cyanus (Asteraceae, Cardueae) in Turkey, with notes on taxonomy and distribution, Phytotaxa 531 (1), pp. 18-40 : 19-20

Cyanus Miller (1754: 4) .

Centaurea sect. Cyanus (Mill.) Candolle (1838: 578) . Centaurea subgen. Cyanus (Mill.) Spach (1841: 11) .

Type:— Cyanus segetum Hill.

Perennial or annual herbs, sometimes with thickened roots or underground stolons, stem erect or ascending, simple or with few branches in perennials, ± copiously branched in annuals. Leaves usually densely covered with tomentose hairs on both sides, rarely glabrescent, undivided or lyrate or pinnatilobate to pinnatifid, median and upper cauline leaves often decurrent. Capitula heterogamous, small to medium-sized, with many florets, solitary at tips of stem and lateral branches. Involucres 5–25 mm wide, oblong, ovoid to subglobose; phyllaries multiseriate, imbricate, herbaceous-membranous, ovate and triangular-ovate to lanceolate-linear, innermost linear, greenish (yellowing on drying), with indistinct veins, sparsely covered with tomentose hairs to glabrous; appendages membranous, triangular, strongly decurrent with a narrow brown to blackish border, rarely without brownish border, pectinate-ciliate, cilia usually silvery, never ending in a firm mucro or spinule. Flowers numerous; central florets hermapherodite, mostly violet-purple, sometimes violet or pink-purple or cream; peripheral florets sterile, blue or purplish blue, sometimes cream or pale pink, usually strongly radiant with (4–)5–8(–15) segments, without staminodes (very rarely with rudimentary staminodes); anthers with small basal appendages, apical appendages obtuse; filament flattened, covered with papilliform hairs; stigma bifid, distinctly exserted from corolla. Achenes oblong, elliptic or oblong-elliptic, rarely elliptic-obovate, medium-sized, 3–6.5 mm long, conspicuously barbate at margin of large hilum. Pappus often much shorter than achenes, rarely longer than achenes, persistent, multiseriate, mostly whitish, double; outer rows with many flat, serrate, or serrate-ciliate bristles, longer inward; inner rows 1 / 4 – 1 / 2 as long as outer ones, with narrow setaceous bristles; rarely pappus absent.