Centaurea cyanus
StarCentaurea cyanus
Synonyms: Centaurea hoffmanniana, Cyanus arvensis, Cyanus dentato-folius, Setachna cyanus, Centaurea cyanus subsp. coa, Centaurea hortorum, Leucacantha cyanus, Cyanus segetum, Centaurea cyanus var. denudata, Cyanus vulgaris, Centaurea pulchra, Centaurea segetalis, Centaurea cyanocephala, Centaurea cyaneum, Jacea segetum, Jacea segetalis, Cyanus cyanus
Western Herbalism Properties
Botanical Description
Centaurea cyanus, the cornflower or bluebottle, is a slender annual herb of the family Asteraceae growing 30 to 90 cm tall, with wiry, grooved, greyish, cottony, branching stems. The narrow, lance-shaped lower leaves are sometimes toothed or lobed, the upper ones linear and entire. The flower heads are borne singly on long stalks, the deep, intense blue outer florets enlarged, flared and deeply slashed into trumpet-like rays surrounding a small cluster of inner reddish-purple florets; pink and white forms also occur in cultivation. It flowers through summer. Once an abundant weed of cornfields across Europe and now much reduced by herbicides but widely grown ornamentally, cornflower favours arable land, roadsides, waste ground and meadows. The bright blue ray florets are dried for herbal teas and as a mild traditional remedy.
Active Constituents
Anthocyanins (protocyanin / cyanidin glycosides)
Anthocyanin pigmentsConcentration: Major pigment fraction of the blue florets
The blue colour of the ligulate florets is due to protocyanin, a metalloanthocyanin complex built from cyanidin-3-O-(6-O-succinylglucoside)-5-O-glucoside together with a flavone, Fe3+ and Mg2+ (stoichiometry 6:6:1:1). These anthocyanins provide antioxidant activity and are the basis for the flower's use as a natural colourant.
Flavonoids (apigenin, quercetin, kaempferol and eriodictyol/taxifolin derivatives)
Flavonoid glycosidesConcentration: ~12 non-anthocyanin flavonoids identified in capitula
Apigenin, quercetin and kaempferol glycosides contribute to the anti-inflammatory, antioxidant and gastroprotective activity reported for flower-head and vegetative extracts.
Phenolic acids (chlorogenic, caffeic, p-coumaric, syringic acids)
Hydroxycinnamic / hydroxybenzoic acidsConcentration: Four phenolic-acid derivatives characterised
Caffeic and chlorogenic acid derivatives add to the radical-scavenging capacity and, with quercetin and apigenin, are associated with the observed gastroprotective effect.
Polysaccharides (arabinogalactans / pectic polysaccharides)
Complex polysaccharidesConcentration: Water-soluble fraction of the flower-heads
Acidic polysaccharides isolated from the flower-heads show anti-inflammatory activity and interfere with the complement system, providing a mechanistic basis for the traditional use in minor ocular and mucosal inflammation.
Sesquiterpene lactones (e.g. cnicin-type)
Sesquiterpene lactonesConcentration: Minor bitter constituents typical of the genus
Bitter sesquiterpene lactones characteristic of Centaurea contribute to mild digestive/bitter-tonic and antimicrobial properties.
Preparation Methods
Infusion / eye lotion
Parts: flower petals, flower-heads
A weak infusion of dried petals (about 1-2 g per cup of just-boiled water, steeped and well strained through fine cloth) has traditionally been cooled and used as a soothing eyewash or compress for tired or mildly inflamed eyes. Because sterility cannot be assured with home preparations, commercial sterile eye products are preferable for any ocular use.
Herbal tea / culinary colourant
Parts: dried petals
Dried blue petals are added to tea blends (e.g. Lady Grey) and as an edible garnish. Steep 1 teaspoon of dried petals in hot water for 5-10 minutes.
Clinical Studies
Anti-inflammatory and immunological effects of Centaurea cyanus flower-heads
Polysaccharides extracted from C. cyanus flower-heads showed anti-inflammatory activity in animal models and interfered with the complement system, supporting the European phytotherapeutic use of the flower-heads for minor ocular and mucosal inflammations.
Historical Texts
European folk ophthalmology (French 'casse-lunettes' / eau de bleuet tradition)
Medieval to early modern EuropeCulpeper, The English Physician (Complete Herbal)
1653References
- Garbacki N, Gloaguen V, Damas J, Bodart P, Tits M, Angenot L. Anti-inflammatory and immunological effects of Centaurea cyanus flower-heads . Journal of Ethnopharmacology (1999) [DOI]
- Lockowandt L, Pinela J, Roriz CL, et al.. Chemical features and bioactivities of cornflower (Centaurea cyanus L.) capitula: The blue flowers and the unexplored non-edible part . Industrial Crops and Products (2019) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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