Musk milfoil

Achillea erba-rotta, commonly known as musk milfoil or musk yarrow, is a small perennial herb in the family Asteraceae native to the European Alps, Apennines, Pyrenees, and Carpathians, where it grows in acidic alpine pastures, screes, and rocky outcrops between 1,500 and 3,000 metres elevation. The plant grows 5 to 25 centimetres tall from a slender creeping rhizome that forms loose mats. Leaves are basal and cauline, sessile, linear to narrowly oblanceolate, 2 to 6 centimetres long, simple and entire to weakly toothed (unlike the deeply pinnatisect leaves typical of most Achillea), bright green, somewhat fleshy, and aromatic with a musky resinous scent when crushed. Stems are erect, simple, slightly hairy, bearing a compact terminal corymb of three to twelve flower heads. Each capitulum is about 8 to 12 millimetres across, with five to nine white ray florets surrounding a small disc of cream-yellow tubular florets. The phyllaries are oblong, with dark brown to blackish scarious margins.