It is an annual plant growing to 40-90 cm tall, with grey-green branched stems. The leaves are lanceolate, 1-4 cm long. The flowers are most commonly an intense blue colour, produced in flowerheads (capitula) 1.5-3 cm diameter, with a ring of a few large, spreading ray florets surrounding a central cluster of disc florets.
GalleriesFlowers and Shrubs: C
Encyclopaedia Britannica (11th ed., vol. 6) (New York, NY: The Encyclopaedia Britannica Company, 1910)