Annual, biennial or perennial
herbs. Leaves entire to pinnate. Flowers small, whitish in terminal or axillary, ebracteate racemes. Sepals not saccate.
Petals 4, vestigial or 0. Stamens 2, 4 or 6. Ovary 2-ovulate. Fruit a subcircular, ovate or elliptic silicula with keeled and winged valves.
Worldwide: c.140 species, cosmopolitan and temperate