It is an annual to biennial herb, pungently scented, grow to 15 to 45 cm tall with the taproot. In India, it is reported to be perennial. The leaves are arranged in a basal rosette form, leaf blades are lanceolate to oblanceolate or spatulate in shape, margins spinous toothed. Flowering shoots divaricately branched, bear more deeply toothed leaves. Flowers are white in cylindrical heads, subtended by a whorl of about 2-3 cm long, 5-6 unequal bracts resembling the upper leaves. Calyx teeth ridged and acute. Petals white or greenish, fruits are ellipsoid or subglobose and greenish. Seeds are semiterete.