A new and distinct Yarrow, Achillea plant named ‘；Firefly Amethyst’；, with billowy habit, dark green, moderately-dissected foliage and large, bright lavender-pink florets that lighten to light pink on heavily-branched compound corymbs, narrow, dark green, fern-like foliage； tall, stiff, heavily branched peduncles with bright lavender-pink florets that lighten to light to very pale lavender, beginning in late June and continuing for about seven weeks and repeating if deadheaded. The new plant is useful for landscaping, as a specimen or en masse and as a cut flower.
