Annual, erect, softly hispid herb with a pungent smell; stem branched, terete with whitish pubescence; leaves opposite or upper ones alternate, petiolate, ovate, acuminate, margins crenate, hirsute on both surfaces; heads small, discoid, homogamous, arranged in dense, terminal corymbs; bracts of involucre 2-3 seriate, linear, subequal, acute, striate; florets many, all tubular, disc florets; corolla white or rarely pale blue, 5-cleft, hairy along the angles; stamens-5, epipetalous, syngenecious, anthers appendaged at apex, obtuse base, filaments slender; ovary 1-celled, 1-ovuled, solitary, basal, obtuse, style arms elongate, obtuse; achenes 5-angled; pappus scales-5, short, free or connate below, awned and often serrate below.