This tall plant (1.5 m) is easy to recognize, with its crown of flat pink or purple flowerheads and its leaves arranged in layers. Its sturdy, upright, unbranched stem is reddish-brown and often speckled. Its leaves, in groups of 4, 5 or 6, form whorls around the stem. They are elongated, with evenly spaced shallow teeth. The leaves have deep veins, making them appear wrinkled, and stiff hairs on their upper surface. The flowers are grouped in inflorescences 12 to 15 cm in diameter. The small dry fruit is dull black, with a tufted crown of hairs.