|This perennial is neat compact mass, 4 to 8 inches tall, which spreads by surface rhizomes, has 3 to 4 inch long grey-green leaves with linear-shaped, toothed margins. Long stalks bear solitary flowerheads 2 inches across with dark purple ray florets and central discs that age to gold. This sun-loving perennial withstands adverse conditions, but grows best in well-drained soil with adequate moisture. Can be grown from seed. Pinch tips of plants to encourage a bushier, sturdier plant.