Asteraceae

Centaurea calcitrapa

Common Names: Star thistle

Plant Form: Annual or biennial shrubby herb. Size: Up to 1 m tall. Stem: Branching, whitish to pale-green, hairy when young becoming more sparse with age. Leaves: Up to 25 cm long initially in rosette, smaller above. Lance shaped, dark green and deeply divided. Wooly when young, becoming less hairy with age. Rough textured. Flowers: Tightly packed purple or pinkish white in stalkless thistle-like heads. Surrounded by greenish to brownish bracts with long sharp spines. Fruit and Seeds: Whitish or greyish seeds with brownish blotches or streaks. Egg-shaped, smooth and without hairs or scales. Habitat: Pastures, cropping kand, roadsides, grasslands, open woodlands, waste land. Distinguishing Features: Distinguished from other Knapweeds (Centaurea species) by having purple flowers in combination with long spines on the bracts surrounding the flower. Also distinguished by having smooth rather than bristled or hairy seeds.