Annual, biennial or perennial taprooted herbs. Hairs simple. Stems erect, leafy. Lower lvs pinnatifid or pinnate, rarely not lobed; upper lvs usually simple. Racemes ebracteate. Sepals erecto-patent, the inner saccate. Petals yellow, veined. Stamens 6, without appendages. Lateral nectaries 2, united, inside bases of lateral stamens; median nectaries 2, ligulate, outside bases of median stamens. Stigma sessile, capitate or weakly 2-lobed. Silicle indehiscent, composed of 2 segments, woody within and corky without; lower segment cylindric or barrel-shaped, 0-2-seeded; upper segment larger, ovoid to turbinate, usually 1-seeded, falling when ripe. Seeds brown, ovoid, not winged.