Description from
Flora of China
Herbs annual, biennial, or perennial, rarely subshrubs. Trichomes absent or simple. Stems erect, rarely prostrate or decumbent, often branched apically. Basal leaves petiolate, rosulate or not, simple, entire or variously pinnately dissected. Cauline leaves petiolate or sessile, often similar to basal. Racemes ebracteate or rarely bracteate, often elongated considerably in fruit. Fruiting pedicels slender or thickened and nearly as wide as fruit. Sepals ovate or oblong, erect or spreading, base of lateral pair sometimes subsaccate. Petals yellow, white, pink, or purple, obovate, spatulate, oblong, or suborbicular, apex obtuse or emarginate; claw often subequaling or longer than sepals. Stamens 6, tetradynamous; filaments not dilated at base; anthers oblong, obtuse at apex. Nectar glands confluent and subtending bases of all stamens; median glands present. Ovules 6-160 per ovary. Fruit dehiscent siliques, linear or rarely lanceolate or subulate, terete or rarely slightly latiseptate; valves papery to subleathery, with a prominent midvein and 2 conspicuous marginal veins, smooth or torulose; replum rounded; septum complete, membranous or rarely thickened, translucent or opaque, veinless or with a midvein; style cylindric, conical, or clavate, persistent, rarely obsolete; stigma capitate, 2-lobed, lobes not decurrent. Seeds uniseriate, wingless, oblong or ovate, plump; seed coat reticulate or papillate, not mucilaginous when wetted; cotyledons incumbent or obliquely so.
About 40 species: N Africa, Asia, Europe, a few species in S Africa and the New World; ten species (one endemic, one introduced) in China.