Description from
Flora of China
Herbs annual, biennial, or perennial, sometimes subshrubs, rarely shrubs or climbers. Trichomes absent or simple. Stems erect or ascending, sometimes creeping, simple or branched basally and/or apically. Basal leaves rosulate or not, simple, entire or pinnately dissected. Cauline leaves petiolate or sessile, base cuneate, attenuate, auriculate, sagittate, or amplexicaul, margin entire, dentate, or dissected. Racemes ebracteate, corymbose, elongated or not in fruit. Fruiting pedicels terete, flattened, or winged, erect or divaricate. Sepals ovate or oblong, rarely orbicular, base of lateral pair not saccate. Petals white, yellow, or pink, erect or spreading, sometimes rudimentary or absent; blade obovate, spatulate, oblong, oblanceolate, orbicular, linear, or filiform, apex obtuse, rounded, or emarginate; claw absent or distinct. Stamens 2 and median, sometimes 6 and tetradynamous or subequal in length, rarely 4 and all median or 2 median and 2 lateral; anthers ovate or oblong. Nectar glands 4 or 6, distinct; median glands always present. Ovules 2 per ovary; placentation apical. Fruit dehiscent silicles, oblong, ovate, obovate, cordate, obcordate, elliptic, or orbicular, strongly angustiseptate; valves veinless or prominently veined, keeled or not, apically winged or wingless; replum rounded; septum complete or perforated, membranous; style absent, obsolete, or distinct, included or exserted from apical notch of fruit; stigma capitate, entire or rarely 2-lobed. Seeds 1 per locule, winged, margined, or wingless, oblong or ovate, plump or flattened; seed coat smooth, minutely reticulate, or papillate, usually copiously mucilaginous when wetted; cotyledons incumbent, rarely accumbent or diplecolobal.
About 180 species: all continents except Antarctica; 16 species (two endemic, two introduced) in China.