Leaves variable, lower ones ovate, upper lanceolate, blade often tapering toward base to form more or less winged petiole. Flower heads one-half to one inch in diameter, white to lavender ray flowers surrounding the yellow disk flowers. Flowers are lilac or white, with four petals, in dense ovoid heads with numerous slender bracts that become stiff-hooked prickles at maturity. Flowers are small, white, four-petaled, borne in racemes, which grow for considerable periods, so that there are often ripe seeds below and flowers at the tip of the raceme. A perennial with fibrous roots developing from the hard enlarged crown.
Seeds are small, oblong, light brown, with a tuft of silky hairs attached to the top.
Leaves are alternate, finely pinnately divided, hairy with distinct carrotlike odor. Flowers small, with five white petals, borne in umbels at ends of branches. The outside seed bearing stalks curve in sharply as they mature.