Achillea collina

Achillea collina, the hill yarrow, is a perennial herb in the Asteraceae family native to dry grasslands, sunny slopes, and roadsides across much of central and southern Europe. The plant is a segregate of the Achillea millefolium aggregate, growing thirty to sixty centimetres tall from a creeping rhizome. The erect, finely grooved stems bear alternate, two- to three-times pinnately divided leaves cut into very narrow linear segments, giving them a delicate feathery appearance. From early summer to autumn the plant produces flat-topped corymbose inflorescences of small composite flower heads; each head consists of four to six short white or occasionally pinkish ray florets surrounding a cluster of cream-coloured disc florets. The whole plant is strongly aromatic, with higher essential oil content (particularly proazulenes) than most other species in the aggregate. Achenes are small and one-seeded.