Perennial herb, 20–50 cm, with erect stems, hispid-pubescent. Leaves oblong to lanceolate, rough-hairy. Inflorescence scorpioid, flowers yellow, often with darker markings in the throat. Corolla funnel-shaped, 1–1.5 cm. Roots thick, reddish inside, yielding a purple dye. Nutlets angular, wrinkled, dark brown to black.