|A spreading and generously blooming perennial that reaches about 24 inches tall and about as wide. Fern like leaves are grayish white, linear, and toothed. Flowerheads are flattish clusters in yellow. Blooms midsummer to fall. This heat and drought tolerant perennial has a fiberous root system and can become invasive. Divide annually to maintain. There are many cultivars of the garden favorite. Butterflies are attracted to this plant. Good cut flower that dries well too. Somtimes referred to as Achillea ageratum.