Fls small, in racemes. Sepals obliquely ascending, not saccate; petals white, < or > sepals or absent; stamens often stunted or reduced to 4 or 2; style obsolescent to distinct; stigma capitate or 2-lobed. Silicles laterally much compressed, 2-seeded; valves keeled or winged above, reticulately veined; septum narrow, ovules pend. from apex of each cell; cots incumbent. Annual to perennial herbs or subshrubs. About 150 spp., some almost cosmopolitan. The N.Z. spp. are mostly endemic.

Annual to perennial taprooted herbs. Hairs simple or 0. Stems procumbent to ascending. Lvs entire or 1-2-pinnatifid. Racemes ebracteate, lf-opposed. Sepals ± spreading, not saccate. Petals either white and inconspicuous, or 0. Stamens 2, 4, or 6, without appendages. Lateral nectaries 0-4, at bases of lateral stamens; median nectaries 2, one outside each median pair of stamens. Silicle small and broad, emarginate or not, angustiseptate, indehiscent or breaking into two 1-seeded segments; valves warty or prominently veined. Seeds ovoid, not winged.

Annual, biennial or perennial taprooted herbs, sometimes subshrubby with stout woody rootstock, rarely shrubs. Hairs simple or papillate or 0. Stems prostrate to erect, leafy. Lvs simple, toothed or 1-2-pinnatifid, or pinnate. Racemes ebracteate. Sepals erect to patent, not saccate. Petals white, rarely yellow or reddish, or often 0. Stamens (0)-2-6, without appendages. Nectaries variable, 6 or 4, tuberculate or filiform. Style long, short or 0; stigma capitate. Silicle ovate, elliptic, obovate, circular or rhomboid, angustiseptate, dehiscent; valves keeled and usually winged, the wings forming a notch at apex and sometimes fused to the base of the style. Seeds ovoid, winged or not, 1 per locule.