Annuals (sometimes winter); not scapose; glabrous. Stems (rarely absent, base of plant forming inflated crown), erect, ascending, subdecumbent, or decumbent, unbranched or branched distally. Leaves basal and cauline; petiolate or subsessile; basal rosulate or not, petiolate, blade margins 1- or 2- (or 3-)pinnatisect, (terminal lobe margin entire or dentate); cauline sessile [subsessile], blade (base not auriculate), margins similar to basal. Racemes (sometimes pedicels originating between basal leaves, bracteate throughout, rachis straight), considerably elongated in fruit. Fruiting pedicels divaricate to ascending, slender. Flowers: sepals (sometimes persistent), erect, spreading, or ascending, (yellowish), oblong, oblong-linear or -lanceolate, lateral pair slightly saccate basally; petals yellow, spatulate to broadly obovate, claw differentiated from blade, (apex rounded or emarginate [obtuse]); stamens tetradynamous; filaments not dilated basally; anthers linear, ovate, or oblong [sagittate]; nectar glands confluent (extending into spreading teeth). Fruits silicles, sessile or shortly stipitate, usually oblong, elliptical, suborbicular, or globose, rarely obovoid, smooth, latiseptate, terete, or slightly inflated; valves (vesicular in S. grandis, thin-papery to leathery), each without midvein, obscurely to prominently reticulate-veined; replum rounded or flattened; septum complete or perforated; ovules 8-44 per ovary; style distinct, (1-12 mm, sometimes flattened basally); stigma capitate. Seeds biseriate, flattened, winged throughout, orbicular; seed coat (coarsely reticulate), not mucilaginous when wetted; cotyledons accumbent. x = 7, 12, 13.