|Hardy and strong rhizome producing perennial with simple, toothed, lance-shaped dark green leaves. Reaches 18 to 24 inches tall. From early to late summer, double flowerheads form loose corymbs to 4 inches across in pure white. This heat and drought tolerant perennial has a fiberous root system and can become invasive. Divide to maintain. Butterflies are attracted to this plant. Good cut flower that dries well, too. Sometimes referred to as Achillea ptarmica 'Schneeball'.