Annual to perennial herbs, rarely woody or shrubby. Leaves alternate or spirally arranged, generally simple and exstipulate, basal often rosulate. Hairs usually simple or branched, sometimes appressed or absent.Inflorescence usually racemose, corymbose. Flowers usually hermaphrodite, hypogynous, actinomorphic, pedicellate and ebracteate. Sepals 4, erect-closed to spreading-open, in two decussate pairs, inner sometimes saccate at the base. Petals 4 (very rarely suppressed), alternating with sepals, free, often with distinct claw, usually yellow, white or lilac, cruciform. Stamens 6 (rarely 4, 2 or even 1 due to suppression, very rarely more than 6), tetradynamous, outer pair short and inner 4 long; filaments some-times winged, toothed or appendaged; anthers dithecous (very rarely monothecous) and fertile. Lateral nectar glands (at the base of the two outer short stamens) almost always present and of various shapes; middle glands present or absent. Ovary bicarpellate, syncarpous, 1-2-celled or with 2-many superimposed cells, 1-many ovuled on two parietal placentas; septum false being formed by the placental outgrowths; style simple, sometimes absent; stigma often capitate, entire to bilobed. Fruit short (silicula) or long (siliqua), dehiscent or indehiscent, usually opening from below by 2 valves which often leave the seeds attached to replum and the false septum, sometimes breaking transversely into 1-few seeded cells, rarely seeds also developing in an indehiscent beak below the style or stigma; valves membranous to coriaceous and thick, plane or inflated, sometimes keeled, winged or appendaged, glabrous or hairy, with 1-many parallel veins (generally rnidvein prominent). Seeds 1-many in 1-2 rows, smooth, granular or reticulated, rarely longitudinally striated, sometimes winged, usually mucilaginous when wet, exalbuminous; radicle accumbent (when it is bent round so as to lie along the edges of the cotyledons i.e. embryo pleurorhizus) or incumbent (when it lies on the face of one cotyledon i.e. embryo notorhizus) ; cotyledons narrowly linear to spathulate, sessile or stalked, rarely plicate or conduplicate (longitudinally folded).